48 GLOSSARY. 



E'quidse (L. equus, a horse). A family of the Perissodactyla 



which embraces the horses and asses. 

 Erecto'res spi'nae (L. erectors of the spine). A series of seven 



muscles in the dorsal region of the trunk. 

 Er'got (Fr. a spur). Another name for the hippocampus minor. 

 Erpetospondy'lia (Gr. erpetos, creeping ; spondulos, a vertebra). 



Applied to those Reptilia which have the dorsal verte- 

 brae and ribs movable. 

 Eth'moid (Gr. ethmos, a sieve; eidos, form). One of the bones 



of the skull, so named because of the perforations in its 



cribriform plate. 

 Ethmovo'merine plate. The anterior plate in the foetal skull, 



formed by the union of the trabeculae. 

 Euere'ta. A group of the Chelonia which comprises the 



turtles. 



Euno'ta. A group of the Lacertilia. 

 Eusta'chian tube. A tube leading from the middle ear to the 



pharynx. 

 Eusta'chian valve. A valve in the right auricle of the heart 



in front of the inferior vena cava. 

 Exalbu'minous (L. ex, without). Applied to seeds destitute of 



albumen. 

 Excrementi'tious (L. excrementum, refuse). Fit only to be 



excreted. 

 Excre'tion (L. ex, out ; cresco, I grow). The removal of waste 



material from the body. 

 Exocci'pital (L. ex, out; occiput, the head). A bone on each 



side of the foramen magnum of the skull ; represented in 



Human Anatomy by the condyloid portions of the 



occipital bone. 

 Exogenous (Gr. exo, outside ; gennao, to produce). Growing 



by addition to the exterior. 

 Exo'podite (Gr. exo, outside; pous, podos, a foot). The 



external terminal joints of the typical appendage in the 



Crustacea. 

 Exorhi'zal (Gr. exo, outside; rhtza, a root). A term applied 



to plants in which the radicle is external to the rest of the 



embryo. 

 Exoske'leton (Gr. exo, outside). The external hard parts, as 



scales, nails, &c., of an animal. 



Exos'mose ") (Gr. exo, without; otheo, I push). The passage 

 Exosmo'sis _) of a fluid from within outwards in the process 



of diffusion through a membiane. 



