Vi THE NAUTILUS. 



Planorbis bicarinatus var. unicarinatus Hald., (PI. 1, 



figs. 6, 8) 3 



Poniaulax turbanicus Dall, n. sp 134 



Planorbis binneyi Tryon, note on 41 



Pterides Pils., n. gen 47 



Pterides bisinulabris Pils., n. sp. (PI. 5, figs. 7, 8) 48 



Pterides pterostoma Pils., n. sp. (PI. 5, figs. 1, 2, 5, 6) . . . 48 



Pterides rhabdus Pils., n. sp. (PI. 5, figs. 3, 4) 48 



Pyramidellidae, New England 39 



Pyramidellidge, more notes of the family 54 



Pyramidella (Sulcorinella) bartschi Winkley, n. sp. (fig.) 39 



Ptissoa (Nodulus) stewardsoni Van., n. sp. (Fig. 1) 65 



Siphonaria lineolata Sowb 132 



Siphonaria naufragum Stearns 132 



Somatogyrus mexicanus Pils., n. sp. (PI. 9, fig. 3) 98 



Sphaerium lineatum Sterki, n. sp 142 



Stearns, Dr. R. E. C. (Obituary and portrait) 70 



Strobilops floridana Pils., n. sp 90 



Squid, suckers from the big (figs. 1-4) 43, 83 



Tornatellinidas, classification of 122 



Tornatellides Pils., n. gen 123 



Tornatellaria Pils., n. sect 123 



Unionidae, a new system of the 114 



Unionidae from an Indian garbage heap 11 



Unionidae from Arkansas and Louisiana 102 



Variation 15 



Valvatida3 of Western North America 104 



Valvata calli Hannibal, n. sp 107 



Valvata whitei Hannibal, n. sp 107 



Valvata humeralis Say 105 



Valvata virens Tryon 106 



Veronicella nilotica Cockerell, n. sp 108 



Viviparus contectus in Philadelphia 60 



Whiteaves, Joseph F. (Obituary) 84 



Zonitoides hermudensis Pils. & Van., (Fig. 1) 63 



