University of N'orth Dakota. 



151 — Bulla ampulla. BubbleShell. 

 152 — Patella sp.? Sea Limpet. 

 153-156 — Busycon perversum (?). 



157 — Buccinum sp.? Whelk Shell. 



India. 



Florida, 



158 — -Buccinum undatum. Whelk. S.I. 



New England coast. 



159 — Tritia trivittata. S. I. 



Buzzard's -Bay, Mass. 



160 — Ilyanassa obsoleta. Black Mud-snail. S. I. 



Newport, R. I., shore. 



161 — Urosalpinx cinera. S. I. 



Wood's Holl, Mass., shore. 



162 — Purpura lapillus. Purple Sea-snail. S. I. 



Wood's Holl, Mass., shore. 



163 — Lunatia heros. Sea-snail, S.I. 



Vineyard Sound, Mass. 



164 — Littorina littorea. Periwinkle. S.I. 



Wood's Holl, Mass., shore. 



165 — Littorina palliata. S. I. 



Wood's Holl, Mass., shore. 



1 60 — Littorina rudis. S. I. 



Wood's Holl, Mass., shore. 



167 — Bittium nigrum. S.I. 



Wood's Holl, Mass., shore. 



1 68 — Crepidula fornicata. Boat Shell or Double Decker. S. I. 



Buzzard's Bay, Mass. 



