Ceolnoth was the 17th archbishop of Canterbury, who played a conciliatory role during the invasions of England by the Danish Vikings. Ceolnoth’s early life is obscure. He was elected and consecrated archbishop probably in 833. At the council of Kingston, Surrey, now Kingston upon Thames, London, in

Ceol: He was succeeded by Ceolwulf and then by Cynegils.

ceorl, the free peasant who formed the basis of society in Anglo-Saxon England. His free status was marked by his right to bear arms, his attendance at local courts, and his payment of dues directly to the king. His wergild, the sum that his family could accept in place of vengeance if he were

rocket and missile system: Design principles: …usually measured by a missile’s circular error of probability (CEP) and bias. CEP uses the mean point of impact of missile test firings, usually taken at maximum range, to calculate the radius of a circle that would take in 50 percent of the impact points. Bias measures the deviation of…

Boletaceae: The cepe (B. edulis) is found in woods and groves of trees during July and August. The 50 species of Suillus form mycorrhizal associations (nutritional “partnerships”) between the filaments of the fungus and the roots of certain trees.

Orlando Cepeda is a Puerto Rican professional baseball player who became one of the first new stars to emerge when major league baseball arrived on the U.S. West Coast in 1958. Cepeda grew up surrounded by baseball: his father, Pedro (“Perucho”) Cepeda, was a power-hitting shortstop who was known

St. Teresa of Ávila ; canonized 1622; feast day October 15) was a Spanish nun, one of the great mystics and religious women of the Roman Catholic Church, and author of spiritual classics. She was the originator of the Carmelite Reform, which restored and emphasized the austerity and contemplative

battles of Cepeda, (1820, 1859), two engagements fought at Cepeda, in the Buenos Aires provincia of Argentina, during the decades of disunity following the declaration in 1816 of Argentine independence. On Feb. 1, 1820, at Cepeda, federalist forces, made up of gauchos from Santa Fe and Entre Ríos

Orlando Cepeda is a Puerto Rican professional baseball player who became one of the first new stars to emerge when major league baseball arrived on the U.S. West Coast in 1958. Cepeda grew up surrounded by baseball: his father, Pedro (“Perucho”) Cepeda, was a power-hitting shortstop who was known

Latin Americans in Major League Baseball Through the First Years of the 21st Century: The 1930s through World War II: …truly a baseball star was Peruchín Cepeda, a powerful infielder who, because he was black, could not play in organized baseball; his own career unjustly forgotten, he is remembered now only for being the father of Hall of Famer Orlando Cepeda.

opalinid: , Cepedea); the locomotor organelles (short, hairlike projections) are arranged in slanting, longitudinal rows. Species of the genus Opalina range from 90 to 500 micrometres in length. Reproduction is sexual by fusion of gametes (syngamy) or asexual by longitudinal splitting with distribution of the nuclei. Opalinids…

flying gurnard, (family Dactylopteridae), any of a small group of marine fish comprising the family Dactylopteridae (order Scorpaeniformes). Flying gurnards are similar to the sea robins, or gurnards (family Triglidae, order Scorpaeniformes), and are sometimes considered as relatives of that group

Cefalù, town and episcopal see, northern Sicily, Italy. It lies at the foot of a 1,233-foot (376-metre) promontory along the Tyrrhenian Sea, east of Palermo city. It originated as the ancient Cephalaedium, which was probably founded as an outpost of the Greek city of Himera and first appeared in

helleborine: …of the two similar genera Cephalanthera and Epipactis (family Orchidaceae). The genus Cephalanthera has about 14 north temperate species, while Epipactis comprises about 21 species native to north temperate areas, tropical Africa, and Mexico. Plants of both genera usually have tall thin stems and crinkled leaves.

helleborine: The phantom orchid (C. austiniae), the only species native to the Western Hemisphere, relies entirely on mycorrhizal fungi for nutrition. The most common British species is large white helleborine (C. damasonium). It has many long thick roots. The petals are borne close together, giving the flower…

helleborine: …most common British species is large white helleborine (C. damasonium). It has many long thick roots. The petals are borne close together, giving the flower a closed appearance. Large white helleborine is self-pollinating and hence does not require the action of an insect as do most other helleborines.

buttonbush, (genus Cephalanthus), genus of at least six species of shrubs or small trees of the madder family (Rubiaceae) native to Africa, Asia, and North America. Buttonbrush plants are named for their fragrant creamy white spherical flowers. They are sometimes used in landscaping and are a

buttonbush: In North America the common buttonbush (Cephalanthus occidentalis) is the best-known member of the genus and can reach up to 6 metres (20 feet) high in marshes and swamps.

Dipsacales: Dipsacus clade: syriaca and the ornamental C. transylvanica, a tall annual that produces large, stiff, globe-shaped, white to bluish flower heads and has divided leaves. Knautia has 60 species, some cultivated, such as field scabious (K. arvensis). Devil’s bit (Succisa pratensis), a blue-flowered perennial, grows wild in European meadows. Its leaves…

bubble shell, any of various marine snails of the order Cephalaspidea (subclass Opisthobranchia of the class Gastropoda). These snails characteristically have thin, globular shells; in some species the shells are embedded in the animal’s body. Many of these snails are active predators, feeding on

fish: Annotated classification: Class Cephalaspidomorphi (Monorhina) Order Petromyzontiformes (lampreys) Without dermal ossification of any sort; pectoral appendages absent; eyes more or less lateral or dorsal; 7 pairs of external gill openings; tail more or less diphycercal. Primarily bottom-dwelling fishes, but suctorial, feeding on blood and juices of

Cephalaspis, extinct genus of very primitive, jawless, fishlike vertebrates found in Lower Devonian rocks (the Devonian Period lasted from 416 to 359.2 million years ago) in Europe and North America. Cephalaspis, one of an early group of vertebrates called ostracoderms, possessed an external bony

cephalic disorder, any of several conditions affecting the structure and function of the human brain and central nervous system that are caused by either abnormalities in fetal development or trauma to the fetus. Cephalic disorders affect infants and children worldwide. There often is no effective

cephalic index, the percentage of breadth to length in any skull. The index is calculated from measurement of the diameters of the skull. The length of the skull is the distance from the glabella (the midpoint between the brows) and the most projecting point at the back of the head. The breadth of

human cardiovascular system: Superior vena cava and its tributaries: …that unite to form the cephalic vein, coursing up the radial (thumb) side of the forearm, and the basilic vein, running up the ulnar side of the forearm and receiving blood from the hand, forearm, and arm. The deep veins of the forearm include the radial veins, continuations of deep…

cephalin-cholesterol flocculation, laboratory test for the nonspecific measurement of blood globulins, a group of proteins that appear in abnormally high concentrations (hyperglobulinemia) in association with certain diseases. The test consists of adding blood serum to a suitably prepared emulsion

melon cactus: …a reddish woolly mass, the cephalium, that forms like a cap atop the plant when it reaches a certain age, varying with the species. Carmine to pink flowers push up through the cephalium, only the tips being visible. The flowers are followed by waxy edible fruits, which are usually pink…

cephalization, the differentiation of the anterior (front) end of an organism into a definite head. Considered an evolutionary advance, cephalization is accompanied by a concentration of nervous tissue (cephalic ganglion or brain) and feeding mechanisms in the head region that serves to integrate

Cephallenia, island, largest of the Ionian Islands, west of the Gulf of Patraïkós. With the island of Ithaca (Itháki) and smaller nearby islands, it forms the nomós (department) of Kefallinía in modern Greece. The island, with an area of 302 square miles (781 square km), is mountainous, and Mount

horseshoe shrimp, any member of the marine crustacean subclass Cephalocarida (class Crustacea), named because of the curving, horseshoelike shape of the body. Only nine species are known, the first of which was described in 1955. A very primitive group, the horseshoe shrimp have no eyes; in

old man cactus: …hairy cacti in cultivation include: yellow old man, or woolly torch (Cephalocereus palmeri); golden old man (Pilosocereus chrysacanthus); old woman (Mammillaria hahniana); Chilean old lady (Eriosyce senilis); and old man of the mountain (Cleistocactus trollii).

old man cactus, (Cephalocereus senilis), columnar species of cactus (family Cactaceae), native to central Mexico. Because of the unkempt wisps of whitish hair along its stem, it is a popular potted plant. It grows well outdoors in Mediterranean climates. Old man cactus usually attains 6 metres

cephalochordate, any of more than two dozen species belonging to the subphylum Cephalochordata of the phylum Chordata. Small, fishlike marine invertebrates, they probably are the closest living relatives of the vertebrates. Cephalochordates and vertebrates have a hollow, dorsal nerve cord,

cephalochordate, any of more than two dozen species belonging to the subphylum Cephalochordata of the phylum Chordata. Small, fishlike marine invertebrates, they probably are the closest living relatives of the vertebrates. Cephalochordates and vertebrates have a hollow, dorsal nerve cord,

pterobranch: Two of them, Rhabdopleura and Cephalodiscus, live in secreted tubes, organized into a colonial structure called a coenecium. The third genus, Atubaria, lives on hydroids. All three genera are rare. About 21 species have been described.

hammerhead shark: The peculiar shapes of sphyrnid cephalofoils appear to serve several purposes. First, the flattened and expanded head acts as a hydrodynamic bow plane that allows the shark to raise and turn its head quickly and sharply. This feature gives the shark enhanced maneuverability to snap up its prey. Second, the…

head, in human anatomy, the upper portion of the body, consisting of the skull with its coverings and contents, including the lower jaw. It is attached to the spinal column by way of the first cervical vertebra, the atlas, and connected with the trunk of the body by the muscles, blood vessels, and

Cephallenia, island, largest of the Ionian Islands, west of the Gulf of Patraïkós. With the island of Ithaca (Itháki) and smaller nearby islands, it forms the nomós (department) of Kefallinía in modern Greece. The island, with an area of 302 square miles (781 square km), is mountainous, and Mount

antelope: Classification: and the four-horned antelope) Subfamily Cephalophinae Tribe Cephalophini (duikers) Subfamily Antilopinae Tribe Neotragini (dwarf antelopes, including royal antelopes,

duiker, (tribe Cephalophini), any of 17 or 18 species of forest-dwelling antelopes (subfamily Cephalophinae, family Bovidae) found only in Africa. Duiker derives from the Afrikaans duikerbok (“diving buck”), which describes the sudden headlong flight of duikers flushed from hiding. No other tribe

graysby, species of sea bass

duiker: …placed in the same genus, Cephalophus. Only the bush, or gray, duiker (Sylvicapra grimmia), which is adapted to the savanna biome, is placed in a separate genus.

duiker: callipygus), bay duiker (C. dorsalis), and white-bellied duiker (C. leucogaster). The white-bellied duiker prefers broken-canopy and secondary forest with dense undergrowth, the black-fronted duiker has elongated hooves adapted to the swampy forest it prefers, and the bay duiker is nocturnal, lying low during the day while…

duiker: …ranges from that of the blue duiker (C. monticola), one of the smallest antelopes, only 36 cm (14 inches) high at the shoulder and weighing about 5 kg (11 pounds), to that of the yellow-backed duiker (C. silvicultor), up to 87 cm (34 inches) high at the shoulder and weighing…

duiker: …pounds), to that of the yellow-backed duiker (C. silvicultor), up to 87 cm (34 inches) high at the shoulder and weighing 80 kg (180 pounds). It appears that the structure of the forest undergrowth selects for shoulder heights that enable duikers and other forest ungulates to move through or beneath…

cephalopod, any member of the class Cephalopoda of the phylum Mollusca, a small group of highly advanced and organized, exclusively marine animals. The octopus, squid, cuttlefish, and chambered nautilus are familiar representatives. The extinct forms outnumber the living, the class having attained

cephalopod, any member of the class Cephalopoda of the phylum Mollusca, a small group of highly advanced and organized, exclusively marine animals. The octopus, squid, cuttlefish, and chambered nautilus are familiar representatives. The extinct forms outnumber the living, the class having attained

umbrellabird, any of three species of cotingas (family Cotingidae, order Passeriformes) of tropical American forests. They are notable for their unique, umbrella-like crest and for the pendant suspended from the throat, which is an inflatable wattle. When displaying, the male spreads the crest to

umbrellabird: The bare-necked umbrellabird (C. glabricollis) of Panama and Costa Rica has a short, round wattle, which is bright red and unfeathered. The latter two species are considered by some authorities to be subspecies of C. ornatus.

umbrellabird: In the ornate umbrellabird (C. ornatus) of the Amazon basin, the wattle is short, triangular, and devoid of feathers on the hindside. In the long-wattled umbrellabird (Cephalopterus penduliger), found west of the Andes in Ecuador and Colombia, the wattle may be 28 cm (11 inches) long and…

umbrellabird: In the long-wattled umbrellabird (Cephalopterus penduliger), found west of the Andes in Ecuador and Colombia, the wattle may be 28 cm (11 inches) long and is entirely shingled with short, black feathers. The bare-necked umbrellabird (C. glabricollis) of Panama and Costa Rica has a short, round wattle,…

cephalosporin, any of a group of β-lactam antibiotics that inhibit the synthesis of a structural component of the bacterial cell wall. The cephalosporins were first isolated from cultures of the fungus Cephalosporium acremonium. Modifications of the β-lactam ring have resulted in more than 20

antibiotic: Cephalosporins: …molecule (7-aminocephalosporanic acid) produced by Cephalosporium acremonium resulted in four generations of cephalosporins.

pitcher plant: Cephalotaceae: The family Cephalotaceae features only one genus with a single species, the Western Australian pitcher plant (Cephalotus follicularis). The plant is a small perennial herb native to damp sandy or swampy terrain in southwestern Australia. Unlike most other pitcher plants, it bears “traditional” leaves…

conifer: Annotated classification: Family Cephalotaxaceae Seed cones highly modified with a few opposite pairs of small bracts, each with a greatly reduced scale remnant strongly dominated by a pair of ovules; only 1 ovule develops into a large seed with a fleshy seed coat; leaves are large yewlike needles…

plum-yew, (Cephalotaxus species), any of about seven species of small coniferous trees and shrubs in the genus Cephalotaxus, comprising the plum-yew family (Cephalotaxaceae). Native to central and eastern Asia, these plants are used in many temperate-zone areas as ornamentals. A fleshy aril

plum-yew: The Chinese plum-yew (C. fortunei) grows to 12 metres (40 feet) in the wild and up to 6 metres (20 feet) under cultivation.

plum-yew: The Japanese plum-yew, or cow’s tail pine (C. harringtonia), grows only in cultivation; it may reach 3 metres (about 10 feet). The Chinese plum-yew (C. fortunei) grows to 12 metres (40 feet) in the wild and up to 6 metres (20 feet) under cultivation.

cephalosporin: , cephalothin and cefalozin) tend to be broad-spectrum antibiotics that are effective against gram-positive and many gram-negative bacteria, including Staphylococcus, Streptococcus, and many strains of Escherichia coli. They have also been used to fight pulmonary infections caused by Klebsiella pneumoniae.

arachnid: Body and appendages: …into two distinct regions: the cephalothorax, or prosoma, and the abdomen, or opisthosoma. The sternites (ventral plates) of the lower surface of the body show more variation than do the tergites (dorsal plates). The arachnids have simple (as opposed to compound) eyes.

Western Australian pitcher plant, (Cephalotus follicularis), carnivorous plant, native to damp sandy or swampy terrain in southwestern Australia, the only species in the flowering plant family Cephalotaceae (order Oxalidales). As with most carnivorous plants, the Western Australian pitcher plant is

Cephalus, in Greek mythology, son of Hermes and Herse, daughter of Cecrops, king of Athens. According to Hesiod’s Theogony, he was beloved by the goddess Dawn (Eos, or Aurora), who carried him off to live with her on Mount Olympus. With his hound, Laelaps (Hurricane), he overcame the vixen of

St. Peter the Apostle was a disciple of Jesus Christ, recognized in the early Christian church as the leader of the 12 disciples and by the Roman Catholic Church as the first of its unbroken succession of popes. Peter, a Jewish fisherman, was called to be a disciple of Jesus at the beginning of

history of photography: Development of the daguerreotype: …Bonfils family in Lebanon, and Kassian Céphas in Indonesia were among the international photographers who set up studios to supply portraits and views during this period.

Cepheid variable, one of a class of variable stars whose periods (i.e., the time for one cycle) of variation are closely related to their luminosity and that are therefore useful in measuring interstellar and intergalactic distances. Most are spectral type F (moderately hot) at maximum luminosity

bot fly: …the North American and European deer nose bot flies (Cephenemyia) and the sheep bot fly (Oestrus ovis). Active larvae, deposited in the nostrils of sheep, often cause a nervous condition called blind staggers. Members of Oestrinae are noted for their swift flying; they are capable of moving at 20–30 km…

Cepheus, constellation in the northern sky, at about 23 hours right ascension and 70° north in declination. It is shaped like a box with a triangle on top. The brightest star, Alderamin (from the Arabic for “right arm”), has a magnitude of 2.5. The star Delta Cephei gave its name to the variable

Cephisodotus the Elder was a Greek sculptor, assumed to be the father of Praxiteles. He made certain statues for the city of Megalopolis, founded in 370 bce. A noted work of his was Eirene (Peace) Bearing Plutus (Wealth), a grouping recalled in Praxiteles’ more-famous Hermes Carrying the Infant

Cephisodotus the Elder: …should not be confused with Cephisodotus the Younger, a son of Praxiteles, noted for portrait sculptures, none of which has survived.

perciform: Annotated classification: Family Cepolidae (bandfishes) Eocene to present. Cepolids are marine, deepwater fishes, basslike, but large mouth is oblique, eyes large, and dorsal and anal fins long, continuous, and high; caudal fin with long rays; body tapers noticeably or with a long tapering body and are shallow-water and deepwater…

guillemot, any of three species of black and white seabirds of the genus Cepphus, in the auk family, Alcidae. The birds have a pointed, black bill and red legs. In British usage, the name guillemot also refers to birds that in America are called murres. Guillemots are deep divers that feed on the

guillemot: The spectacled guillemot (C. carbo) breeds from Japan to the Kuril Islands. The two spotted eggs of guillemots are laid in a crevice, where the young remain for six weeks until they can fly.

charadriiform: Auks (suborder Alcae): The breeding behaviour of the pigeon guillemot (Cepphus columba) is fairly typical of the family. This species breeds on islands and coasts of the North Pacific, south to central California. It nests between rocks or in holes in cliffs, uses burrows of other birds, or digs its own tunnels with…

guillemot: …the three species is the black guillemot, or tystie (C. grylle). It is about 35 cm (14 inches) long and is coloured black with white wing patches in the breeding season. In winter it is fully white below and speckled brown and white above. The black guillemot breeds around the…

Robert: Expansion of the duchy: …Gregory VII, entering into the Concordat of Ceprano, which confirmed the commitments of the earlier Council of Melfi. Even the Byzantine court drew closer to him and went as far as trying to establish a familial relationship with Robert. The Byzantine emperor Michael VII, in need of Robert’s help to…

telephone: Personal communication systems: Meanwhile, the European Conference on Posts and Telecommunications (CEPT) had begun work on another personal communication system, known as DECT (Digital Enhanced Cordless Telecommunications, formerly Digital European Cordless Telephone). The DECT system was designed initially to provide cordless telephone service for office environments, but its scope soon…

Balkrishna Doshi: …Environmental Planning and Technology (CEPT University) in 2002. Students assisted in designing each new addition, using similar forms and materials so that the entire campus felt cohesive.

William K. Estes: …with whom he developed the conditioned emotional response (CER) paradigm, a method of studying conditioned animal behaviours. In their landmark 1941 study, rats were repeatedly given food (a naturally positive stimulus) after pressing a lever. Eventually, an electric shock was applied immediately after the food presentation, which caused the lever…

New Zealand: Trade: …provided the basis of the Australia and New Zealand Closer Economic Relations Trade Agreement (known as CER), signed in 1983. That agreement eventually eliminated duties and commodity quotas between the two countries and was seen by some as the first step toward integrating their economies. New Zealand also has a…

telescope: Evolution of the optical telescope: Cer-Vit, for example, was used for the 4.2-metre (165-inch) William Herschel Telescope of the Roque de los Muchachos Observatory in the Canary Islands, and Zerodur was used for the 10.4-metre (410-inch) reflector at the Gran Telescopio Canarias in the Canary Islands.

blood doping: …abused, and newer forms—such as continuous erythropoiesis receptor activator (CERA), which was developed for persons suffering from kidney disease—challenged existing detection technologies. In 2008 CERA was detected for the first time among cyclists competing in the Tour de France. It was also found in three track-and-field athletes, two cyclists, and…

peak oil theory: By contrast, the influential Cambridge Energy Research Associates (CERA) estimated in 2005 that current global production capacity would not hit peak before 2020.

Cera dynasty, rulers of an ancient kingdom in what is now Kerala state, southwestern India. Cera was one of the three major kingdoms of southern India that constituted Tamilkam (territory of the Tamils) and was centred on the Malabar Coast and its hinterland. The other two dynasties were the

Michael Cera is a Canadian actor especially known for his comedic portrayals of offbeat and often awkward characters. Cera first garnered attention as George-Michael Bluth in the acclaimed sitcom Arrested Development (2003–06, 2013, 2018–19), and he later starred in such popular comedies as

Michael Cera is a Canadian actor especially known for his comedic portrayals of offbeat and often awkward characters. Cera first garnered attention as George-Michael Bluth in the acclaimed sitcom Arrested Development (2003–06, 2013, 2018–19), and he later starred in such popular comedies as

Ceram, island, part of the Moluccas (Maluku) archipelago, eastern Indonesia. It is located between the Ceram Sea (north) and the Banda Sea (south) and is west of New Guinea and east of Buru Island, across the Manipa Strait. Ceram has an area of 6,621 square miles (17,148 square km) and is

long-horned beetle, (family Cerambycidae), any of about 25,000 species of beetles (insect order Coleoptera) whose common name is derived from the extremely long antennae of most species. These beetles occur throughout the world but are most numerous in the tropics. They range in size from 2 to 152

ceramic composition and properties, atomic and molecular nature of ceramic materials and their resulting characteristics and performance in industrial applications. Industrial ceramics are commonly understood to be all industrially used materials that are inorganic, nonmetallic solids. Usually they

advanced structural ceramics: Transformation toughening: Ceramics such as transformation-toughened zirconia (TTZ) are often referred to as ceramic steel because the strain, or change in dimension, in response to stress behaviour resembles that of steel instead of a brittle ceramic. Also, the underlying phase transformation is called martensitic, after a similar transformation in rapidly…

materials science: Metal-matrix and ceramic-matrix composites: For the latter applications, ceramic-matrix composites (CMCs) are seeing increasing use, although the technology for CMCs is less mature than that for PMCs. Ceramics consist of alumina, silica, zirconia, and other elements refined from fine earth and sand or of synthetic materials, such as silicon nitride or silicon carbide.…

Alfred University: …internationally renowned New York State College of Ceramics, a statutory college of the State University of New York system, was established in 1900. The founder of the college was the English potter Charles F. Binns.

sphingolipid: …most simple sphingolipids are the ceramides (sphingosine plus a fatty acid), widely distributed in small amounts in plant and animal tissues. The other sphingolipids are derivatives of ceramides.

sphingolipid: Ceramide oligosaccharides also contain several molecules of carbohydrate; an example is globoside from red blood cells.

Fabry’s disease: …deposits of a glycosphingolipid (ceramide trihexoside) in the blood vessels. These deposits in turn produce heart and kidney disturbances resulting in a marked reduction in life expectancy. Distinctive clusters of dark red granules in the skin on the abdomen and knees of victims led early students of the disease…

moss animal: Evolution and paleontology: The ceramoporoids, a group belonging to the order Cystoporata, flourished during the Ordovician and evidently were the progenitors of a more advanced group, the fistuliporoids, which were successful until the end of the Permian (299 million to 251 million years ago).

Giovanni Battista Crespi was one of the chief Lombard painters of the 17th century, whose work is important in the early development of Lombard realism. In 1586 Crespi went to Rome, where he stayed until 1595. While in Rome he formed a friendship with the Milanese cardinal, Federigo Borromeo, who

dinosaur: Cerapoda: Cerapoda is divided into three groups: Ornithopoda, Pachycephalosauria, and Ceratopsia. The latter two are sometimes grouped together as Marginocephalia because they share a few features, including a bony shelf on the back of the skull.

dinosaur: Cerapoda: Cerapoda is divided into three groups: Ornithopoda, Pachycephalosauria, and Ceratopsia. The latter two are sometimes grouped together as Marginocephalia because they share a few features, including a bony shelf on the back of the skull.

cerargyrite, gray, very heavy halide mineral composed of silver chloride (AgCl); it is an ore of silver. It forms a complete solid-solution series with bromyrite, silver bromide (AgBr), in which bromine completely replaces chlorine in the crystal structure. These are secondary minerals that

Cerastes, genus of venomous, desert-dwelling snakes of the viper family, Viperidae. There are two species, the horned viper (C. cerastes), which usually has a spinelike scale above each eye, and the common, or Sahara, sand viper (C. vipera), which lacks these scales. Both species are small (seldom