GLOSSARY 673 



Trochanter, third, a hook-like process on the outer side of the shaft of the 

 femur, near the middle of its length. 



Trochlea, the pulley-shaped lower end of the humerus for articulation with 

 the fore-arm bones. 



Trunk vertebrae, those of the body, the dorsals and lumbars. 



Tubercle, an articular projection on a rib, connecting with the transverse pro- 

 cess of a dorsal vertebra. 



Tuberosities (of the humerus), heavy projections from the upper end of the 

 bone, in front of the head. 



Tubulidentata, the Aard Vark ; an order of placental mammals. 



Tylopoda, Camels and Llamas ; suborder of Artiodactyla. 



Tympanic, a bone forming the support of the ear-drum and usually inflated 

 into a hollow capsule. 



fTypotheres, see fTypotheria. 



fTypotheria, an extinct suborder of the fToxodontia. 



Ulna, the external bone of the fore-arm. 



Unciform, the external bone in the lower row of the carpus ; supports the 



fourth and fifth digits, or ring and little fingers. 

 Unconformity, the relation between two groups of strata, one of which was 



deposited upon the worn surface or upturned edges of the other. 

 Ungual phalanx, the terminal joint of a digit, which supports the claw, nail 



or hoof. 

 Unguiculata, clawed mammals ; cohort of Monodelphia. 

 Ungulata, hoofed mammals ; cohort of Monodelphia. 

 Ungulates, see Ungulata. 

 Uterus, the womb. 



Vagina, the genital canal of the female. 



Variety, a more or less constant group within a species. 



Vertebra, a joint of the backbone. 



Vertebral column, the backbone. 



Viviparous, producing living young. 



fZeuglodontia, an extinct order of Cetacea. 



Zygapophyses, the projecting processes, by means of which successive verte- 

 brae are articulated together. 

 Zygomatic arch, a bony bridge from the eye-socket to the hinder part of the 



2x 



