374 GLOSSABY OF TECHNICAL TEEMS. 



Ventral Jins. The paired fins behind or below the pectoral flns in fishes, 



corresponding to the posterior limbs in the liiglier vertebrates. 

 Ventral plates. In serpents, tlie row of plates along the belly between 



throat and vent. 

 Ventricle. One of the thick-walled chambers of the heart. 

 Versatile. Capable of being turned either way. 

 Vertebra. One of the bones of the spinal column. 

 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. 



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. 

 Xiphisternum. Tip of the sternum. 

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



behind. 

 Zygoma. The malar or cheek bone. 



EXPLANATION OF SIGNS AND ABBREVIATIONS. 

 I. Fishes. 



i. = Total length in inches of a well-grown example. 



D. = Dorsal fin. 



2d D. = Second dorsal fin. 



P. = Pectoral fins. 



V. = Ventral fins. 



A. = Anal fin. 

 C. = Caudal fin. 



B. =Branchiostegals. 



Vert. = Vertebrae. The number is usually divided into abdominal and 

 caudal vertebrae; the latter having the haemapophyses united, 

 forming haemal spines. Thus Vert. 10 -|- 14, the usual number 

 in typical fishes, means 10 abdominal and 14 caudal vertebrae. 

 $ = Male. 

 9 = Female. 



Roman numerals used with abbreviations for the fins indicate the 

 number of spines or inarticulate rays in a fin. Arabic numerals indicate 

 the number of soft rays. In a fin containing both spines and soft rays, 

 a comma ( , ) separating the numerals indicates that the two kinds of 

 rays are continuous, or more or less connected. A dash ( — ) indicates 



