GLOSSARY. 877 



Transverse Crosswise. 



Trenchant Compressed to a sharp edge. 



Truncate Abrupt, as if cut squarely off. 



Tubercle A small excrescence, like a pimple. 



Tympanum Drum of the ear ; external in some Batrachia. 



Typical Of a structure the most usual in a given group. 



Ulna The inner or posterior bone of the fore-arm. 



Ungulate Provided with hoofs. 



Unguiaulate Provided with claws. 



Unicolor Of a single color. 



UrostegesThe plates underneath the tail of a serpent. 



Vent The external opening ot the alimentary canal. 



Ventral Pertaining to the abdomen. 



Ventral fins The paired fins behind or below the pectoral fins 



in fishes, corresponding to the posterior limbs in die higher 



vertebrates. 



Ventral plates Gastrosteges in serpents. 

 Ventricle One of the chambers of the heart. 

 Versatile Capable of being turned either way. 

 Vertebra One of the bones of the spine. 

 Vertical Up and down. 

 Vertical fins The fins on the median line of the body ; the dorsal, 



anal and caudal fins. 



Vertical plate Central plate on the head of a serpent. 

 Villiform Said of the teeth of fishes when slender and crowded 



into velvety bands. 

 Viscous Slimy; viscid. 

 Vitta A band of color. 

 Viviparous Bringing forth living young. 

 Vomer In fishes, the front part of the roof of the mouth ; a bone 



lying immediately behind the premaxillaries. 

 Web The vane of a feather, on either side of the rhachis or 



" stem " ; also, the membrane connecting the toes. 

 Zygodactyle Yoke-toed ; having the toes in pairs two in front, 



two behind. 

 Zygoma The malar or cheek bone. 



