34 GLOSSARY 



Cris'ta acus'tica (L. acoustic crest). A small projection in the 



ampullae of the membranous semicircular canals of the ear. 

 Cris'ta galli (L. cock's comb). A ridge in the ethmoid bone 



of the skull to which the falx cerebri is attached. 

 Cris'ta il'ii (L. crest of the ilium). One of the borders of the 



iliac bone. 

 Cris'ta ure'thrse (L. crest of the urethra). A small ridge in the 



lining membrane of the urethra. 

 Cris'ta vesti'buli (L. crest of the vestibule). A vertical ridge in 



the vestibule of the ear. 

 Crocodi'lia A group of the Reptilia which includes the 



crocodiles, alligators, &c. 

 Crocodi'lidae (Gr. krokodeilos, a crocodile). A subdivision of 



the Crocodilia which comprises the crocodiles proper. 

 Crossoptery'gidae (Gr. krossos, a fringe; pterux, a wing, fin). 



A sub-order of Ganoid fishes. 

 Cro't&phite (Gr. krotdpJws, the temples). A term sometimes 



applied to the temporal artery, vein, and muscle. 

 Cru'cial (L. crux, criicis, a cross). In the shape of a cross. 

 Cru'ra cfi'rgbri (L. legs of the cerebrum). Two bundles of nerve 



fibres containing grey matter, which form the floor of the 



tier of the brain. 

 Cms (L. the leg). That portion of the lower or posterior 



extremity of the Vertebrata which lies between the femur 



and the tarsus. Also applied to any leg-like process. 

 Crus'ta petro'sa (L. stony crust). A substance resembling 



bone which coats the fangs of teeth, and in some cases 



fills up depressions in the enamel. 

 Crypt (Gr. krupto, I conceal). A term sometimes applied to 



simple tubular glands. 

 Cryptoga'mia (Gr. kruptos, hidden ; gamos, marriage). Plants, 



the reproductive organs of which are not readily visible, 



and which are sometimes termed " flowerless." 

 Cryptor'chismus (Gr. krupto, I conceal; orchis, a testicle). 



Retention of the testes in the abdomen. 

 Crystalline lens. The lens-shaped transparent body which is 



contained in the eyeball, and which assists in focussing 



the rays of light upon the retina. 

 Crystalloids (Gr. krusta/los, crystal ; cidos, form). Substances 



which are generally capable of being crystallized, and the 



solutions of which pass readily through membranes. 

 Ctenobranchia'ta (Gr. ktcis, ktinos, a comb ; bronchia, a gill). 



A group of the Branchiogasteropoda. 



