52 DRYM^EUS, MEXICO AND CENTRAL AMERICA. 



(Scutalus) iodostylus FISCH. & CROSSE, Miss. Scient. Mex., Mol- 

 lusca, i, p. 539 Balimus iodostylus STREBEL, Beitr. Mex. Land- 

 und Siissw.-Conch. v, p. 70, pi. 12, figs. 8a, 8fr. 



S. W. Mexico : Santa Efigenia, Tehuantepec (Sumichrast). 



The variety stolli is so much like D. sulcosus as to suggest specific 

 identity. Von Martens writes as follows: Dr. 0. Stoll states, in his 

 MS. notes, that this species is very common at the above-mentioned 

 elevations, but apparently dees not occur on the most elevated ridges 

 between Totonicapan and Tecpam, nor lower than 6000 feet on the 

 terraces of the Cordillera at Santa Maria and San Martin. In dry 

 weather it conceals itself on the lower face of blades of grass, but 

 during and after rain it creeps about freely. 



The relative proportion of the breadth to the length of the shell is 

 very variable, as is also the size in this species. Its chief character- 

 istics are the coarse plaits of the last whorl, the preceding whorls 

 being remarkably smoother, and the rose-color of the apertural wall 

 and of the columella. The last-mentioned character distinguishes 

 it with few exceptions from 0. sulcosus, which is the corresponding 

 form in the elevated plain of Central Mexico. The rose color, how- 

 ever, is somewhat variable ; it is never wanting, and more or less 

 intense on the upper half of the columellar margin, and extends 

 sometimes upwards on to the parietal wall and beneath to near the 

 base of the aperture; in some specimens the whole interior of the 

 aperture is pale rose-colored, and a stripe which on the outside is 

 dark brown appears in the interior intense reddish-brown. 



D. HEGEWISCHI (Pfeiffer). PI. 1, figs. 81, 82, 83, 84, 85. 



Shell ovate, thin but moderately strong, very narrowly perforate ; 

 whitish, usually stained in places with light brown, and having un- 

 equally spaced, narrow, brown longitudinal streaks which do not ex- 

 tend to the suture above, and are often obsolete at the base. Surface 

 shining, irregularly wrinkle-striate, and showing fine, subobsolete 

 spiral lines under the lens. Spire conic, the apex obtuse, with typi- 

 cal Drymczus sculpture ; whorls 5J, but slightly convex, the last oval. 



Aperture long-ovate, light brown or yellowish inside, showing dark 

 streaks ; peristome thin and unexpanded, acute ; columellar margin 

 reflexed for a short distance above, nearly closing the perforation. 



Alt. 25, diam. 12^, length of aperture 14 mill. 



Central Mexico: environs of Mexico, in tierra fria, on Cactus 



