GLOSSARY. 



227 



those deposits in which many of the mammals belong to 

 species now extingt; in this country usually called Pleis- 

 tocene or Post-pliocene. See Alluvium. 



Fig. 18.— Skull of Great Ant-eater, na. Nasal; ma. Maxilla; p.m. Pre-maxilla. 

 Observe the entire absence of teeth, and the incomplete 7ygomatic arch (s.a.). 



Fig. 19. — Skull of Sloth. /./. Jugal or malar process ; a downward process 

 from the jugal or cheek bone. z.a. Incomplete zygomatic arch. 



DIPHYODONT (Gr. dis, twice, phyo, to become, and 

 odous, odontos, a tooth). Furnished with two sets of teeth 

 in succession, as man. 



DISCOIDAL (Gr. diskos, a disc, and eidos, form). 

 Having the form of a disc; more or less round and flat. 



DISTAL (Lat. disto, to stand apart or away from). 

 Farthest away from the trunk or centre; as, the wrist- 

 bones are at the distal ends of the radius and ulna. 



DIURNAL (Lat. diurnus, belonging to the day). 

 Active by day, not by night. 



DORSAL (Lat. dorsum, the back). Pertaining to the 

 back. — Dorsal region, the back part of the body from the 

 neck to the last of the false ribs. 



EDENTATA (Lat. e, without, dens, a tooth). An 

 order of mammals in which the middle incisors are always 

 wanting, and in some members of 

 which there are no teeth at all. See 

 figs. 18 and 19. 



EDENTATE. A member of the 

 Edentata. 



EMBRYO (Gr. en, in, and bryo, 

 to swell). A young animal before 

 birth. 



EMBRY07,OGY (embryo, and Gr. 

 logos, discourse). The science which 

 deals with the development of em- 

 bryos. 



EMBRYONIC. Pertaining to an 

 embryo. 



EOCENE (Gr. eos, dawn, and 

 kainos, new). Belonging to the oldest 

 division of the Tertiary rocks. See 

 Geological Table, vol. i. p. 23. 



EPIGLOTTIS (Gr. epi, upon, and glotta, the tongue). 

 A cartilaginous plate behind the tongue, which during the 

 act of swallowing covers the glottis or slit-like opening 

 into the larynx at the top of the windpipe, and thus pre- 

 vents foreign bodies from entering the latter. 



EPITHELIUM (Gr. epi, upon, and thele, the nipple). 

 A thin and delicate kind of cuticle like that which covers 

 the nipple; specifically, a tissue composed of one or 

 more layers of cells covering any free surface of the 

 body, including the walls of internal cavities, such as 

 the mouth, and such passages as have an internal free 

 surface, like the nasal passages, respiratory organs, &:c. 

 The epidermis or scarf-skin is only a slightly modified 

 epithelium. 



EURASIAN. Belonging to the combined continent 

 of Europe and Asia. 



EVOLUTION. The process by which one species is 

 believed to be developed by natural descent from pre- 

 existing species. 



EVOLUTIONARY. Pertaining to evolution, or per- 

 taining to the theory that new species arise by natural 

 descent from pre-existing ones. 



FACIAL REGION. See under Skull. 



FAUNA (Lat., the goddess of fields, cattle, &c). A 

 collective name for the animals belonging to a region or 

 epoch; as, the fauna of Great Britain; the Triassic fauna. 



FELINE (Lat. felis, a cat). Used in the text in the 

 sense of a member of the genus Felis, or (as an adjective) 

 belonging to the genus Felis. 



FEMUR (Lat.). The thigh-bone; the bone of the 

 upper part of the hind-leg. 



FETLOCK. A tuft of hair growing behind the pastern 

 joint of horses, and also the joint itself. 



FIBULA (Lat, a brooch). The outer of the two 

 bones of the lower hind-leg, corresponding to the ulna of 

 the fore-leg or fore-arm. See figs. 20-23. 



FLIPPER. The fore-limb modified so as to serve 

 for a paddle in swimming, as in seals, whales, and sea- 

 cows. 



FLORA (Lat., the goddess of flowers). A collective 

 name for the plants belonging to a region or epoch. See 

 Fauna. 



FORM. Used in botany and zoology as a general 

 term for a species or variety. 



Fig. 20. — Skeleton of the 

 Fore-limb or Flipper of 

 the Whalebone Whale. 



Fig. 21. — Same of the Fig. 22. — Same of the Fig. 23.— Same of the Seal. 

 Caaing Whale. Dugong. 



r, Radius; u. Ulna; h. Humerus. I.-V. Digits. 



FOSSA (Lat., a ditch). A depression. — Temporal fossa, 

 the depression in the skull in the region of the temple. 

 See fig. 24. 



FRCENUM LINGUAE (Lat., bridle of the tongue). 

 The ligament or fold of the mucous membrane which is 



