150 BULl MULL'S. 



glyptus as Peronteus to Lissoacme, or PUcolumna to typical forms of 

 Orthotomium. 



Subgenus N^ESIOTUS Alb. (Vol. xi, p. 94). 



Prof. W. H. Dall has given a supplemental report on Galapagos 

 snails, based on specimens collected by Messrs. R. E. Snodgrass and 

 E. Heller (Proc. Acad. Nat. Sci. Phila. 1900, p. 88); describing 

 the following new species : 



B. SNODGRASSI Dall. PI. 24, fig. 2. 



Bulimulus having the general form of B. perspectivus Pfr., with 

 a distinct suture and eight polished moderately convex whorls ; apex 

 attenuated, nucleus livid, with an apical dimple and fine regular rib- 

 bing which becomes obsolete on later whorls; there is also on the 

 first four whorls more or less spiral sculpture of microscopically fine 

 lines, which also disappear on later whorls ; subsequent whorls 

 smooth or -with fine incremental lines; upper whorls dark purplish 

 brown, later ones a little paler, with a narrow paler band just behind 

 the suture, which on the last whorl becomes strongly marked, with a 

 dark reddish narrower band on each side of it, and traces of another 

 at the suture; in some specimens the dark coloration covers the 

 whole surface on each side of the peripheral pale band, but inside 

 the aperture the bands can always be distinguished; base rounded 

 about a well-marked umbilicus ; aperture small, ovate, marginally 

 thickened and slightly expanded, but not reflected ; a narrow band 

 of callus over the body connects the posterior ends of the lips ; pillar 

 broad, slightly swollen, external coloration visible in the throat. 

 Alt. of shell 17, of aperture 5.2, diam. of shell 6, of aperture 4 mill. 

 (Dall). 



Galapagos: Hood Island (Snodgrass and Heller), numerous. 



Bulimulus snodgrassi DALL, Proc. A. N. S. Fhila. 1900, p. 90, 

 pi. 8, f. 2. 



This species is smaller than B. perspectivus and differently colored, 

 but belongs to the same group. 



B. APPROXIMATES Dall. PI. 24, fig. 3. 



Shell belonging to the type of B. nux and B. rugulosus with seven 

 pretty evenly tapered whorls, with a distinct suture; nucleus as in 

 the last species, livid, but the early whorls bear no traces of revolv- 



