86 DRYMJEUS, MEXICO AND CENTRAL AMERICA. 



apex of the same color. Surface somewhat shining, smooth, showing 

 fine, superficially engraved spiral lines under a strong lens. Spire 

 high, straight-sided, the apex obtuse, with typical Drymceus sculpture. 

 Whorls 6^-7, but slightly convex. 



Aperture small, ovate, typically showing the bands inside; peri- 

 stome acute, thin, unexpanded ; columellar lip triangularly reflexed 

 above ; columella straight. 



Alt. 28, diam. 12, length of aperture 12 mill. 



Alt. 21J, diam. 10, length of aperture 9 mill. 



Yucatan: Campeche, on the shore (Morelet); Tabi, S. of Merida, 

 in the interior (F. D. Godman, Febr., 1888); Ruins of Labna (Heil- 

 prin Exped.). 



Bulimus tropicalis MORELET, Test. Noviss. i, p. 9 (1849). PFR., 

 in Martini & Chemnitz, Syst. Conch. -Cab., ed. 2, Bulimus* p. 198, 

 pi. 55, figs. 5, 6 ; Monogr. Helic. Vivent. iii, p. 424. Bulimus 

 (Pyrgus) tropicalis PFR., in Malak. Blatt. ii, p. 159 (1855) Bui- 

 imulus (Liostraeus) tropicalis FISCH. & CROSSE, Miss. Scient. Mex., 

 Mollusca, i, p. 504, pi. 20, figs. 7, 8 Bulimulus tropicalis STREBEL, 

 Beitr. Mex. Land- und Siissw.-Conch., v, p. 95. PILSBRY, Proc. 

 Acad. Nat. Sci. Phila., 1891, p. 315. Otostomus tropicalis MAR- 

 TENS, Biol. Centr. Amer., p. 233. 



The specimens collected by Morelet (pi. 6, figs. 21, 22) have three 

 brownish-red bands on the last whorl, and are 27 to 28 mill, long, 

 with 7 w r horls. Those taken at Labna by the expedition from the 

 Academy (fig. 23) are smaller, 21-22 mill, long, with the bands pink, 

 the upper two almost obsolete, and with a pink band just behind the 

 columella, which is somewhat stained with the same tint. The young 

 are a little keeled and the bands are more brown. This is the only 

 sinistral species of Drymaus known. 



GROUP OF D. ALTERNANS. 



D. ALTERNANS (Beck). PI. 15, figs. 38, 39, 40. 



Shell narrowly perforate, ovate-conic, thin but moderately solid ; 

 white or faintly buff-tinted with five spiral brown bands ; the upper 

 one narrow, bordering the white-edged suture, the fifth forming a 

 rather large umbilical patch. Surface glassy, smooth, with slight 

 growth wrinkles and close, fine, engraved spiral striae, in some speci- 

 mens subobsolete in places. Spire conic, the apex rather obtuse, 

 having typical Drymseus sculpture. Whorls 5^, moderately convex. 



