92 GLOSSARY. 



Odon'toid (Gr. odous, odontos, a tooth). Applied to the tooth- 

 like process of the second cervical vertebra. 

 OdontS'phora (Gr. odous, odontos, a tooth ; pJwreo, I bear). A 



division of the Mollusca comprising those animals which 



possess an odontophore. 

 Odon'tophore (Gr. odous, odontos, a tooth; phoreo, I bear). A 



strap-like masticator) crgan supplied with sharp teeth found 



in some Mollusca. 

 (EsS'phagus (Gr. oiso, future of phero, I bear ; phagein, to eat). 



The tube, leading from the pharynx, by which the food 



passes from the mouth to the stomach. 

 Olec'ranon (Gr. dlene, the elbow; kranion, the top of the 



head). The summit of the ulna which forms the elbow. 

 Olein (L. oleum, oil). A neutral fatty substance. 

 Oligochae'ta (Gr. oligos, small ; chaite, hair, mane). A division 



of the Invertebrata which comprises the earth-worm and 



the freshwater-worms. 

 Olivary (L. olive-shaped body). Like an olive in shape, as 



the olivary body of the medulla oblongata, and the olivary 



process of the sphenoid bone. 



O'masum (Gr. omos, raw). The third stomach of a ruminant. 

 Omen'ta (L. omentum, the caul). Applied to certain folds of 



the peritoneum. 

 O'mo-hy'oid (Gr. onws, the shoulder ; hyoid bone). A muscle 



stretching from the scapula to the hyoid bone. 

 Omos'tegite (Gr. bmos, the shoulder; stego, I cover). The 



posterior division of the carapace in the Branchiopoda. 

 O'moster'num (Gr. omos, the shoulder ; sternon, the breast). 



A median process in the Batrachia developed from the 



coraco-scapular cartilages. 

 Ompha'lo-mgsara'ic (Gr. omphalos, the navel; ntesos, the 



middle). The name given to certain arteries and veins in 



the fo3tus. 

 Ompha'lo-mesentg'ric (Gr. omphalos, the navel; mesentery). 



The name of vessels which in the fcetus return blood from 



the walls of the umbilical vesicle. 

 Oogo'nium (Gr. don, an egg; gonos, seed). The germ cell in 



some fungi which on impregnation becomes an oospore. 

 Oos'tegites(Gr. <w#,an egg; */<#, I cover). Plateswhich in some 



Crustacea enclose a cavity in which the eggs are hatched. 

 Oper'cular (L. ope mil nm, a lid). Relating to the operculum. 



Opercular gills are those attached to the hyoidean arch in 



some fishes. 



