GLOSSARY 371 



Cephalochorda {sef a lo kor' da). A subphylum of Chordata, comprising the species 

 of Amphioxus. For definition see Chapter XII. 



Cephalopod {sef a lo pod). One of the group Cephalopoda, to which the cuttle- 

 fishes, squids, and nautiU belong. 



Cephalopoda {sef a lop' o da). A class of Mollusca, comprising the octopi, squids, 



cuttlefishes and nautili, animals in which the foot is developed into a head-like 



structure with eyes and a circle of arms. 

 Cephalothorax {sef a lo tho' raks). A fused head and thorax, found in crayfishes and 



their aUies. 

 Ceratite {ser' a tite). An extinct cephalopod having a coiled shell and crooked 



sutures; named from the genus Ceratites. 

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



common name ceratite is derived from this genus. 

 Cercaria {ser ka' ri a). The tailed larval form of the liver fluke Fasciola (and similar 



forms) which is produced by a redia and which develops into the adult fluke. 

 Cerebellum {ser' e beV lum). A division of the brain of vertebrates developed on the 



dorsal side anterior to the medulla. 

 Cerebrum {ser' e brum). 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 {ser' vi kal). Pertaining to the neck. 



Cestoda {ses to' da). A class of Platyhelminthes, comprising the tapeworms. For 

 definition see Chapter XII. 



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

 chffita. 



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

 represented chiefly by the arrow-worm Sagitta. 



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

 the earthworm and sand-worm belong. 



Chara {ka'ra). A genus of aquatic plants. 



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



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



Chemotropism {kern ot' ro piz' tn) . The response of an organism to chemical sub- 

 stances. 



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. 



Chlamydomonas {klam' i dom' o nas). A genus of unicellular flagellate chlorophyll- 

 bearing organisms. 



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

 earthworm. 



Chlorophyll {klo' rofil). The green substance in chloroplasts through whose agency 

 photosynthesis occurs. 



Chloroplast {klo' ro plast). A green plastid. 



Cholesterin {ko les' ter in). A substance of fat-like texture common in bile, the chief 

 constituent of gall stones, and found also in blood, nerve tissue, egg yolk, etc. It 

 is often classed with the lipoids. 



Choline {ko' lin). A hydroxide common in plant tissues and in many animal cells, as 

 egg yolk and nerve tissue, in various combinations. 



