154 BULIMULUS-BOSTRYX-LISSOACME. 



variation in the development of the sculpture, some specimens being 

 conspicuously granulate, others very obsoletely so. The compara- 

 tive width also varies. 



B. SCALARIOIDES Philippi. PL 46, figs. 59, 60. 



Shell perforate, oblong-turrited, solid, striatulate and sculptured 

 with rather remote strong folds (about 10 on the last whorl). Opaque r 

 white. Spire turrited, the apex rather obtuse; suture profound. 

 Whorls 6, convex, the last nearly equalling two-fifths the length of 

 the shell. 



Aperture subvertical, oblong, flesh-colored inside ; peristome 

 simple, the right margin unexpanded, arcuate above; columella 

 brownish, shining, dilated above, nearly appressed. Alt. 12*,diam. 

 5 mill. ; aperture, alt. 5 mill. (Pfr.). 



Pataz (Paz), and Province of Conchucos, Peru.. 



B. scalarioides Phil, in sched., PFR., Malak. Bl.,xiv, 1867, p. 77 ;. 

 Monogr., vi, p. 140. HIDALGO, Journ. de Conchyl., 1870, p. 53;. 

 xxiii, 1875, p. 128, pi. 7, f. 4. 



Hidalgo gives the number of longitudinal folds as 10 to 14 on the 

 last whorl. 



Section 8. Lissoacme Pilsbry, 1896. 



Lissoacme PILS., Nautilus, ix, p. 114 (Feb. 1, 1896). Scutalus< 

 Thaumastus and Rhabdotus in part of authors. 



Bulimuli of rather stout, ovate contour, with the smooth, glossy 

 first whorl and initial dimple of Bostryx. Aperture over a third, 

 usually about one half the total length, the outer lip simple and un- 

 expanded (with very few exceptions), the columellar lip dilated, col- 

 umella foldless or nearly so ; umbilicate or perforate. Type B. ery- 

 throstomus. 



The forms included in this section (which like the foregoing sec- 

 tions of Bostryx is a division for convenience rather than a sharply 

 defined group) are especially characteristic of Chili, Peru, and the 

 adjacent portion of Bolivia. Few occur so far north as Ecuador, 

 Eastward, the group extends entirely across Argentina, but here the 

 species are conspicuously thin-shelled, while the trans- Andean types 

 are of solid and earthy texture. 



North American Bulimuli of the B. dealbatus and sehiedeanus 

 group closely resemble the Lissoacme species in form and texture, 

 but the characters of the earliest whorls are completely different.. 



