VI 



rage 



Watson, Rev. Robert Booo, B.A., F.R.S.E., F.L.S., RG.S. 

 MoUusca of the ' Challenger ' Expedition ; — 



Part XVI. Fams. FissuRELLiDiE and OoccuLiNiD^. (With 



a woodcut.) 26 



Part XVII. Fam. Pyramidellidje. (With a woodcut.) . . 112 

 Part XVIII. Order Opisthobranchia, M.-Edw., Fam. Tor- 



NATELLID^ 284 



Part XIX. Fam. BuLLiDiE 319 



Part XX. Fam. Bullid^ (continued), and Fam. Aplysiidje. 341 



