618 



COMPARATIVE ANATOMY 



Turritellidce, 6 

 Tylaster, 297 

 Tylodina, 10 



UlNTACRINUS, 309 



Umbrella, 10 

 Umbrellidce, 10 

 Uncini, 182 

 Unio, 17 



Margaratiferus (Margaritana), 17, 

 35 



pinctorum, 17 

 Unionidce, 17 

 Unionince, 50 

 Uniqphora, 299 

 Urechimis, 293 

 Urns, ciliated, 437 

 Utriculus, 180 



VAGINULID&, 8 

 Vaginulus, 45 

 Valvaster, 299 

 Valvatidce, 6 

 Veliger, larva, 1, 257 

 Velum, 250 

 Veneracea, 18 

 Venericardia, 17 

 Veneridce, 18 

 Venus, 18 



Verinetidce, 6 



Vermetus, 108, 248 



Vertebral ossicles (Oph.), 356 



Verticordiidce, 51 



Vitrina, 8 



Volutidce, 6 



Vulsella, 17 



WACHSMUTH and Springer's rule, diagram, 



374 

 Wandering cells (amoebocytes) (Echiu.), 



415 

 Water lung (Hoi.), 487 ; pore (Scaph.), 



221 ; pores (Crin.), 377 



XENOCRINUS, 306 

 Xenophoridce, 6 

 Xylopliaga, 21 



TOLDIA, 14 

 Ypsilothuria, 409 



ZEUGOBRANCHIA, 4 

 Zonites, 8 

 Zoroaster, 298 



fulgens, apical system, 326 

 Zoroasteridce, 298 

 Zygoneury, 137 



THE END 



Printed by R. & R. CLARK, LIMITED, Edinburgh. 



