404 PROCEEDINGS OF THE ACADEMY OF [1899. 



what resembles B. ashmuni, B. dalliana and B. jyrototyims, but in 

 none but the first of these is the separation so complete. B. 

 ashmuni, however, has the folds stronger and the latter part of the 

 last whorl contracted as in B. contmcta. B. dalliana is a whitish 

 species with the parietal folds distinctly united and a basal denticle 

 developed, while B. jrrototypus is a larger form, with smaller and 

 united parietal folds. 



In having the parietal folds quite separated, B. r/(oac?.s-treseml)]es 

 several east Asian representatives of Bifidaria, which are more 

 primitive than most of the American species. 



The figures are from camera lucida drawings. 

 Strobilops hubbardi stevensoni n. var. 



Shell similar to S. hubbardi A. D. Brown, but darker, smoother, 

 more widely umbilicated and constantly with three lamellae within 

 the basal wall. 



Dark reddish chestnut, very glossy; sculptured with very fine 

 striae above, the base smoother with microscopic spirals. Whorls 

 4, quite convex, the last well rounded at the periphery which is 

 above the middle; umbilicus wide, the latter third of the last 

 whorl deviating tangeutially, somewhat as in many Polygyras. 

 Through the base at the last fourth of the body- whorl may be seen 

 three lamellee, the outermost below the periphery, rather long, and 

 somewhat oblique; the others shorter. Parietal wall showing one 

 strong, emerging lamella above, and a much weaker one below 

 (the latter emerging only in fully mature shells), both of them 

 running inward about one-thiixl of a whorl. Aperture broadly 

 lunate-oval, oblique, with whitish, expanded and subrefiexed lip. 



Miami, Florida. 



This form differs from S. hubbardi chiefly in its wider umbilicus 

 and smoother surface, though the darker color and smaller number 

 of lamellee visible through the base are further distinguishing 

 features, ^Nlr. Webster (Nautilus, vii, pp. 84, 94) has shown 

 hubbardi to vary in the number of lamellaj. At Mr. Rhoad's re- 

 quest, it is named in honor of Mr. James Stevenson, an energetic 

 naturalist of Miami, Florida. 

 Glandina truncata minor, n. var. 



Similar to the typical form, but constantly much smaller. 

 Whorls 5f . 



