GLOSSARY 375 



Ceratites (scr' a ti' teez). A genus of extinct cephalopods with crooked sutures; the 



common name ceratite is derived from this genus. 

 Ceratium candelabrum (se ra' shi um can' de la' brum). A species of protozoon which 



forms linear colonies. 

 Cerebellum. A division of the brain of vertebrates developed on the dorsal side 



anterior to the medulla. 

 Cerebrum, The anterior division of the brain in vertebrates. In man it forms the 



greater part of the brain but is smaller in other vertebrates. 

 Cervical. Pertaining to the neck. 

 Cestoda. A class of Platyhelminthes, comprising the tapeworms. For definition see 



Chap. 19. 

 Chaetogaster (ke' to gas' ter). A genus of worms, phylum Annelida, subclass Oligo- 



chaeta. 

 Chaetognatha {he tog' na tha). A group of marine animals of uncertain kinship, repre- 

 sented chiefly by the arrowworm Sagitta. 

 Chaetopoda {ke top' o da). A class of worms (Annelida) provided with setae, to which 



the earthworm and sandworm belong. 

 Cheloniidae {kel' o ni' i dee). A family of turtles. 

 Chelydidae {ke lid' i dee). A family of turtles. 

 Chelydridae {ke lid' ri dee). A family of turtles. 

 Chitin {ki' tin). A horny substance forming the outside skeleton of insects and many 



other animal parts. 

 Chiton [ki' ton). A genus of primitive mollusks, having a shell of several pieces. 

 Chloragogen cells {klo' ra go' jen). The cells of the outer layer of the intestine of the 



earthworm. 

 Chlorophyll. The green substance in chloroplasts through whose agency photosyn- 

 thesis occurs. 

 Chloroplast. A green plastid. 

 Cholesterol {ko les' ter ol). A substance, one of the solid alcohols, found in many 



animal tissues. 

 Chordata {kor da' ta). A phylum of animals including the vertebrates and a few 



others. For definition see Chap. 19. 

 Chromatin {kro' ma tin). The deeply staining substance of the nucleus of a cell. 

 Chromoplast. One of several kinds of colored structures or organs found in many 



plant and some animal cells. 

 Chromosome. One of the rodlike or rounded bodies into which the chromatin of a 



nucleus is resolved at the time of cell division. 

 Chrysemys {kris' e juis). A genus of turtles. 

 Ciliate. A class of the protozoa, in which both young and adult stages are provided 



with cilia. 

 Ciliophora {siV i of o ra). A subphylum of protozoa, members of which are covered 



with a pellicle, have a fixed mouth, and are usually covered with cilia; example, 



Paramecium. 

 Cilium. A minute hairhke motile structure occurring on the surface of certain cells. 

 Circular canal. A channel passing around a medusa near its margin. 

 Circulation. The movement of the blood through a system of vessels. 

 Circumpharyngeal connectives {ser' kum fa rin' je al) . Nerve cords in the earth- 

 worm connecting the brain with the ventral nerve cord; so called because they 



pass around the anterior end of the pharynx. 

 Citellus tridecimlineatus {si tel' lus tri des' im lin' e a' tus). A species of ground 



squirrel. 

 Class. A subdivision of a phylum ; a group of higher rank than the order. 



