364 APPENDIX III 



BLASTOCOEL (G. blastos, a sprout, plus koilos, cavity), the cavity of the 

 blastula, the segmentation cavity. 



BLASTODERM (G. blastos, plus derma, skin), the germinal membrane giving 

 rise to the embryo; found in vertebrate eggs with meroblastic cleav- 

 age; blastoderm is in distinction to extra-embryonic tissue. 



BLASTULA ((j. dim. of blastos), a hollow sphere of cells formed by early 

 cleavages; in the amniotes generally, a flat plate of cells. 



BODY STALK, an embryonic stalk connecting the embryo with the yolk 

 sac; its external cell layers are continuous with those of embryo and 

 amnion. 



BRACHIAL (L. brachium, arm), an adjective referring to the arm or its 

 structure. 



BR.'^CHY (G. short), a prefix; brachycephahc, brachydactylous. 



BRANCHIA (G. branchia, gills), a combining form in hemibranch, branchial, 

 Branchiostoma; branchia may be used as a noun. 



BRONCHIOLE (G. dim. of bronchos, windpipe), a minute bronchial tube. 



BRONCHUS (G. bronchos, windpipe), one of the larger divisions of the 

 trachea. 



BUCCA (L. cheek or mouth) ; as buccal cavity. 



BULLA (L. a bubble), a hollow bony growth, as the tympanic bulla. 



BURSA (L. purse or wallet), a pouch or sac, as the bursae of a joint. 



CAECUM (L. caecus, blind), a pouch open at only one end; particularly 



the pouch at the juncture of the small with the large intestine. 

 CALVARiUM (L. skull), the brain case. 

 Cambrian (L. Cambria, for Northern Wales), the oldest geological period 



of the Paleozoic Era. 

 CANINE (L. canis, dog), the first mammalian tooth posterior to the incisors; 



they are unusually long in the carnivores. 

 CAPILLARY (L. capillus, a hair), any hair-like structure; particularly the 



smallest blood vessels lying between the arterioles and venules. 

 Capitosaurus (L. caput, head, plus G. sauros, a lizard), a genus of extinct 



stegocephalian amphibia. 

 C.-^RBONiFEROUS (from carbon, or coal measures), a general name for the 



upper periods of the Paleozoic Era, in which most of the coal beds are 



found. 

 cardia (G. kardia, heart), pertaining to the heart; cardiac, pericardium. 

 CARINA (L. keel), a projecting, keel-like structure, as the carina of a 



dogfish chondrocranium, or the keel of a bird sternum. 

 Carinatae (L. carina, a keel), a sub-class of birds having a keel on the 



sternum, the flying birds. See Ratitae. 

 Carnivora (L. caro, (earn), flesh, plus voro, to devour), an order of 



flesh-eating mammals with large canine teeth; dogs (Canidae), cats 



(Felidae), bears (Ursidae), etc. 

 CAUDA (L. tail), usually in adjectival form; caudal, caudad; or, cauda 



equina. 

 Cenozoic (G. kainos, new, plus zoon, animal), the most recent of great 



geological eras, following the Mesozoic. 

 CENTRUM (L. center), a heavy central region of a vertebra, from which 



spring the spinous and transverse processes. 

 cephale (G. kephale, head), a combining form; cephalic, cephalad. 



