332 



THE ELASMOBRANCH FISHES 



Unpaired arteries, 186 



Ureter, 287, 289, 291, 295; relation of, to 



collecting tubules, 294, 295; relation 



of, to male Wolffian duct, 296 

 Urinary papilla, 289, 290, 291, 296, 303 

 Urinary sinus, 289, 291, 294, 295; ducts 



to, 294-295; horns of, 295, 296; walls 



of, 296 

 Urinary system, in Elasmobranchs in gen- 

 eral, 292-300; in Heptanchus, 287-289 

 Urinary vesicle, 294 

 Urogenital sinus of male, 291; relation 



of, to seminal vesicle, 302; relation of, 



to vas deferens, 302 

 Urogenital system, in Elasmobranchs in 



general, 292-310; in Heptanchus, 287- 



291 

 Vroloplius halleri, fig. 9; cf. Acanthias, 8, 



10-12; poison gland of, 28 

 Uterine septum, 309 

 Uterus, 290, 306-309 ; blood supply to, 193, 



307; lining of, 307, 308; partitions of, 



308 ; relation of, to embryo, 307-309 

 Utriculus of ear, 259, 272, 273 



Vagus nerve, 225-227, 244-245; divisions 

 of, 225-227, 244-245; lobes of, 236; 

 nucleus of, 236; visceral sensory fibers 

 of, 236 



Valves, oviducal, 306; of heart, 160-161, 

 171, 172; of spiral intestine, 124, 126, 

 139, 140; of uterus, 306; of veins, 204 



Valvular intestine, 124, 126, 139-140; ar- 

 teries to, 166, 167, 188, 190; veins of, 

 201, 210-211 



Vas deferens, 290, 291; relation of, to 

 Wolffian duct, 290, 296 



A'asaefferentia, 290, 301-302 ; origin of, 301 



Vascular sacs, 208, 221, 233 



Vasodentine, 35, 130 



Veins, 170, 198, 204; cf. arteries, 170, 204; 

 of body wall, 202, 204; from digestive 

 tract, 200-201, 204, 210-213; from 

 head, Heptanchus, 198, 204; of heart, 

 215-216; of kidney, 208, 210; of skin, 

 202-203, 204, 216-217; of tail, Hep- 

 tanchus, 199 ; walls of, 170, 204 



Velum, 233 



Vena limitans, 210 



Vena profunda, 217 



Venous system, in Elasmobranchs in gen- 

 eral, 204-218; in Heptanchus, 198-203 



Ventral aorta, 161, 172, 175 



Ventral bundles, 89, 97 



Ventral constrictor muscles, 91, 104-105; 

 nerves to first ventral constrictor, 243 



Ventral cutaneous veins, 203, 217; rela- 

 tion of, to cloacal vein, 217 



Ventral gastric artery, 166, 187 



Ventral gastric vein, 201, 211 



Ventral horn of cord, 222, 237, 238; cells 

 of, 238 



Ventral intercalary piece, 48 



Ventral intestinal artery, 167, 188; ab- 

 sent in rays, 188 



Ventral intestinal vein, 201, 210; tribu- 

 taries of, 201, 210-211 



Ventral lobe of pancreas, 124, 138 



Ventral longitudinal muscles. See Hypo- 

 branchials 



Ventral myelonal vein, 208 



Ventral root nerve, 227; foramen of, 48 



Ventricle, 160, 161, 170, 171, 179 ; arteries to, 

 163-164, 172; walls of, 160-161,170, 171 



Ventrolateral bundles in medulla, 235 



Ventrolateral muscle bundles, 89, 97 



Ventromedian muscle bundles, 97 



Vertebrae, 69, 70, 71, 72; in Alopias, 69 



Vertebral plate, in rays, 71 



Vertebromuscularis artery, 192, 193-194 



Vertebrospinalis artery, 192 



Vertebrospinal vein, 210 



Vesicula seminalis, 302 



Vesicles of Savi, 274, 281 



Vessels of Thebesius, 215-216 



Vestibular nerve, 273 



Villus, arteries of, 307; of intestine, 140; 

 nutriment from, 307-308; of uterus, 

 307-309; veins of, 307 



Visceral arches, 44-^7, 62-67; in embryo, 

 62; muscles to, 100-108 



Visceral nerve (X), 225 



Visceral sensory fibers, 236 



Visceral skeleton, of Elasmobranchs in 

 general, 62-69; of Heptanchus, 44—47 



Visceromotor nucleus, 236, 240 



Vitelline vein, 212, 213 



Vitreous body (humor), 268 



Vitrodentine, 35 



Viviparous, 307 



White blood cells, 170 



White matter of cord, 237 



Wolffian duct, 287, 289, 294, 295, 296, 297 

 modified as vas deferens, 290, 296, 301 

 relation of, to collecting tubules, 294 

 relation of, to vas deferens, 302 



"Wonder net," 181 



