of Mollusca, 454 ; Medusa, 



247, 748. 

 Venus > 488. 

 Vermes, 578-589. 

 Vermetus, shell, 474. 

 Vermiform appendix, 29. 

 Vermiformia, 691, 703-704. 

 Veronicella, accessory genital 



organs, 11,8. 

 Vertebra, Mammalia, 14 ; 



Aves, 59, 63 ; Python, 72 ; 



Rana, 80, 82 ; Teleostei, 



94, 99-102 ; development 



of in, 99 ; Vertebrata, 339, 



340,361,374,383,397,414. 

 Vertebrata, 335-359. 

 Vesicula prostatica, 30. 

 Vesiculatae, 247. 

 Vibraculum, 237. 

 Vibrissae, 359. 

 Visceral arches, v. Branchial 



arches. 

 Visceral ganglionic cord of 



Urochorda, 442 n. 



INDEX. 



Viscero-pericardial sac of 



Cephalopoda, 462. 

 Vitellarium, xxiii. 

 Volvox, 845, 846. 



W. 



Wagnerella, 872. 

 Waldheimia, 702. 

 Water-pores of Echinoder- 



mata, 546; Crinoidea, 575. 

 Water-vascular system of 



Echinodermata, 546, 551, 



560,565,568,574; oiAste- 



rias, 193, 194. 

 Weber's organ, 30. 

 Wing, Periplaneta, 142 ; In- 



secta, 153, 155, 156, 499, 



500. 

 Wolffian duct, 354, 355, 356. 



X. 



Xiphisternum, 60, 362, 384, 

 Xiphosura, 529. 



937 



Y. 



Yellow cells, in Radiolaria, 



881 ; v. Symbiosis. 

 Yoldia, gills, 488. 



Zaphrentis, 744. 



Zoaea, 172, 538. 



Zoantharia, 733-744. 



Zoanthidae, 735. 



Zonites, pedal nervous sys- 

 tem, 120. 



Zoochlorelld) 243. 



Zoocyst, 915. 



Zooeciuin, 234. 



Zooxanthella.) 243 ; v. Yellow 

 cells. 



Zoroaster, 563. 



Zygantrum, 73. 



Zygapophysis, 340. 



Zygobranchia, 482. 



Zygosphene, 73. 



THE END. 



