GLOSSARY. 25 



Chev'ron bones (Fr. a rafter). Downward processes of the 



caudal vertebrae of some of the Vertebrata which enclose 



the backward continuation of the aorta, 

 Chias'ma (Gr. chiazo, I mark with the letter X, chi). A crossing, 



as the chiasma of the optic nerves. 

 Chilog'natha (Gr. cheilos, the upper lip ; gnatJws, the upper jaw). 



A division of the Myriapoda which comprises the Milli- 

 pedes, in which the mandibles are covered by a kind of lip. 

 Chilo'poda (Gr. cheilos, the upper lip ; pous, podos, a foot). A 



division of the Myriapoda which comprises the 



Centipedes. 

 Chi/tin (Gr. chiton, a coat of mail). The horny substance 



found in the exoskeletons of many of the Invertebrata. 

 Chla'mydate (L. chldmydatus, clothed in the chlamys, a large 



woollen upper garment). A term applied to those 



Branchiogasteropods which are provided with a mantle. 

 Chlo'rophyll (Gr. chldros, green ; phyllon, a leaf). The (usually 



green) colouring matter of plants, developed only under 



the influence of light. 

 Chloro'sis (Gr. chldros, green). The green-sickness. A disease 



due to retention of the menses. 

 Cho'anae na'rium (Gr. and L. the funnels of the nose). The 



openings of the posterior nares. 

 Choles'terin (Gr. chole, bile; stear, suet). A fatty substance 



found in bile and in some of the tissues. 

 Chon'dro-cra'nium (Gr. chondros, gristle ; kranion, skull). The 



cartilaginous model of the future skull in the vertebrate 



embryo. 

 Chondros'teidae (Gr. chondros, gristle). A sub-order of Ganoid 



fishes. 

 Chor'da dorsalis (L. the dorsal or back cord). The embryonic 



structure, which forms the axis round which the bodies of 



the vertebras are developed, and which in some of the 



Vertebrata persists through life. 

 Chor'da tym'pani (L. cord of the drum). A small branch of the 



facial nerve, which traverses the drum of the ear and 



supplies the submaxillary gland. 

 Chor'dae tendi'nese (L. tendinous cords). The cords which are 



attached on the one hand to the papillary muscles of the 



ventricles, and on the other to the flaps of the auriculo- 



ventricular valves of the heart. 

 Cho'rion (Gr. cJiorion, skin). The outer membrane which in 



the Mammalia surrounds the fcetus. 



