VI 



THE NAUTILUS. 



Shells and Mastodon 34, 55, 100 



Sigaretus oldroydii, notes on . . . . .85 



Stepbanoda Iheringi Ancey, n. sp. . . . . .17 



Stephanoda latastei Ance}', n. sp. . . . . .17 



Strobilops hubbardi stevensoni Piisbry, n. var. . . .40 



Strorabns, attempt to define the natural groups of . 76, 93 

 Thomson, John H. (Biographical note) . . . .113 



Thysanophora hornii Gabb ....... 98 



Tres Marias Islands, Mexico, Natural History of . . 19 

 Turritellidae, Viviparous Miocene . . . . .68 



Unios of the Sabine River . . . . . . .79 



Onionidse in a tunnel ........ 130 



Unio conjugans Wright, n. sp. . . . . . . 89 



Unio Danielsii Wright, n. sp. . . . . . .31 



Unio dispalans Wright, n. sp . . . . . . .50 



Unio Hagleri Frierson, n. sp. (Plate II.) .... 109 



Unio Harperi Wright, n. sp. ...... 6 



Unio Kingii Wright, n. sp. . . . . . . . 138 



Unio polymorph us Wright, n. sp. 42 



Unio rotulatus Wright, n. sp. ...... 22 



Unio (Lampsilis) Rovirosai Piisbry, n. sp. . . .140 



Unio singularis Wright, n. sp. . . . . . .75 



Unio Tinkeri Wright, n. sp. ...... 7 



Unio unicostatus Wright, n. sp. . . . . . . 6y 



Yeronicella, notes on Jamaican . . . . . .131 



Viviparous miocene Turritellidae . . . . .68 



Zonitidae collected by J. H. Ferriss in Arkansas and the 



Choctaw Nation 107 



Zunitoides neomexicanus Cockerell it Piisbry, n. sp. . . 114 



