134 GLOSSARY. 



CHELICERS; ("x 1 ?^ claw ; Kfpas, horn, antenna\ the modified antennse of Scorpions. 



CHELONIA (xeA.t6"7, a tortoise), an order of Reptiles. 



CHIASMA (xiW/ua, a crossing, fr. x'^C^j to mark with a x), the commissure of the 



optic nerves which takes place in most Vertebrata. 

 CHILOGXATHA (xeA.os, lip ; -yvdOos, jaw), an order of Myriapoda otherwise known 



as Diplopoda. 



CUILOPODA (xeiXos, lip ; TTOVS, foot), an order of Myriapoda, otherwise Syngnatha. 

 CHIBLERA (xiV<"f>> a monster like a goat), a genus of Elasmobranchiate fishes 



which has been made into a separate family, the Holocephali. 

 CHITIN (X'TCOS/, a tunic), the horny covering of Insects and other Annulosa. 

 CHLOROPHYLL (xA.wp<k, green ; (pv\\ov, leaf), the colouring matter of leaves. 

 CHORION '-x&piov, a skin Lat. cvrium), the vascular membrane wliich surrounds 



a vertebrate foetus. 

 CiCATRictLA (dim. of cicatrix, & scar), the opaque spot on the surface of a 



fecundated yelk. 



CILIA (pi. of cilium, an eyelash), microscopic filaments which move rhythmically. 

 CIRRIPEDIA (cirrus, a curl of hair ; peg, a foot), a group of Crustacea in which 



several of the legs become cirrous : placed by Cuvier among the Mollusca. 

 CLAVICLE 'clavicula, dim. of clams, a key , the collar-bone of the pectoral arc-h or 



shoulder girdle in Vertebrata, in birds called the merrythought. 

 CLOACA (a sewer), the common duct into which the rectum, urethra and genital 



canals open in the Sauropsida and Monotremata. 

 COCHLEA (KOX^IS, n snail), applied to part of the internal ear in the higher 



Vertebrata, from its spiral shape in Man. 

 CCELENTERATA (jcotAos, hollow ; evTtpa, viscera), a group of animals which differ 



from those below them in having a hollow digestive cavity. 

 CtENOSARC (Koiv6s, common ; <rdp, flesh), the common stem of a hydroid poly- 



pidom. 

 OENURUS (Koiv6s, ovpd, tail), the hydatid form of the wandered scolex of the dog's 



tapeworm with its deuto-scolices attached. 

 COLEOPTERA (ico\e6s, a sheath ; irrtpiv, a wing), an order of Insects with the 



membranous wings (second pair) enclosed in sheaths formed by the elytra. 

 COLUMELLA (dim. of columna, a pillar), the bone of the ear present in several 



Amphibia and most Sauropsida, which answers to the stapes in Mammalia. 

 CONDTLE (/covSuAos, a knuckle), the articular surface of a bone, especially of the 



occiput. 

 COPEPODA (KC&H-J?, an oar ; irovs, foot), an order of Crustacea, including, beside the 



group so named by Latreille and Milne-Edwards, most of the Epizoa or 



Ichthyophfhira. 

 CORACOID (/copo, a crow, from its resemblance to a crow's beak in man), the 



second clavicle found in Reptiles, Birds, and Monotremata. 

 CORALLIGENA (jcopaXAtov, coral ; yev- , root of yiyvo/j.a.i, produce), an order of 



Actinozoa. 

 CORPUS CALLOSCM, "the firm body," the great transverse commissure of the 



cerebral hemispheres in Mammalia. 

 CORRODENTIA (con and rodere, gnaw), the family of insects to which the destructive 



" white ants " belong. 



CORTICAL (cortex, bark), external opposed to medullary. 

 COTYLEDON (Ko-rvX-nStav), a cup-shaped hollow, applied in anatomy to the tufts of 



a ruminant placenta. 

 CBASPEDOTE (/cpa<nre5J&>, to surround with a border), " the naked-eyed " Medusse, 



