DRYM^EUS, MEXICO AND CENTRAL AMERICA. 39 



Silam, Ticul, Tekanto, Sitilpech and Uxmal (Heilprin, Baker 

 et al.). 



Seems to range from the State of Tamaulipas to Yucatan, where, 

 in the northern part of the peninsula at least, it is a common species. 

 Although extremely variable in coloration, form and size, it is readily 

 recognized, and not closely allied to any species but the following. 



Fig. 35 is copied from a drawing by Mrs. Say of the type speci- 

 men, which is still extant in the collection of the Academy. It is 

 the largest shell of a considerable series before me. 



Binney records serperastrum from Texas, but without giving any 

 definite locality. Its occurence north of the Rio Grande requires 

 confirmation, as it has not been found in Texas during the last forty 

 years or more. 



D. ZIEGLERI (Pfeiffer). PI. 40, figs. 4, 5, 6. 



Shell oblong-conic, rather slender, perforate; opacpue white, uni- 

 colored or with a few oblong spots arranged in vertical rows, or 

 interrupted bands (six in number when most developed) of dark 

 brown: surface lightly striatulate and showing fine faint spiral lines 

 under the lens. Spire long, apex obtuse, yellowish-corneous, with 

 typical Drymaus sculpture. Whorls 6, slightly convex, the last 

 somewhat tapering below. 



Aperture less than half the shell's length, oblong, the lip slightly 

 expanded below, columellar lip reflexed ; columella nearly straight. 



Alt. 29, diam. 12^, length of aperture 13^ mill. 



Mazallan, N.-W. Mexico, also Altata (Stearns). 



Bulinmlus zieyleri PFH., P. Z. S., 1846, p. 113, exclusive of var. /?. 

 Orthalicus zieyleri CPR., Maz. Catal., p. 177. BitUmulus zieglen 

 BINNEY, L. and F.-W. Sh., N. A., i, p. 193, f. 336 STEARNS, 

 Proc. U. S. Nat. Mus. xvii, p. 165 Bulimus calif ornicus Reeve. 



The description and figures 4, 5, are from Mazatlan specimens 

 in the collection of the Academy. These vary from whitish without 

 markings to sparsely spotted, and finally to as fully developed a pat- 

 tern as D. serperastrum. Perhaps Carpenter's Orthalicus f mexicanus 

 (Maz. Cat. p. 177) was a banded specimen; it was a solitary shell. 

 Fig. 6 is copied from Binney's figure of a specimen received from 

 Pfeiffer. 



Closely allied to D. serperastrum, but more slender, smoother, 

 more polished than most specimens of that species, and showing 



