72 DRYMJEUS, MEXICO AND CENTRAL AMERICA. 



< This fine species is distinguished by its thin pure white shell, 

 with not very numerous round brown spots ; these are arranged on 

 the last whorl in four spiral rows, on the preceding whorl in three, in 

 the one before that in two rows, those of the second row being often 

 a little larger than the others. The spots are placed rather distant 

 one from the other, and they can also be regarded as being arranged 

 in vertical rows, forming interrupted stripes from the suture towards 

 the umbilicus, but this arrangement is not so regular as the spiral 

 one. The spiral striae of the shell are exceedingly fine. The aper- 

 ture is pure white, the peristome very slightly reflected. 



" The average length of the shell is 28-30 mill.; but one figured 

 by Strebel (fig. 12) attains even 34J mill., and one reported by Herr 

 Ho'ge, from Mexico, the locality of which is not especially stated, is 

 only 24 mill. long. The breadth of the shell is equal to the length 

 of the aperture and to about half the length of the whole shell." 

 (Martens. ) 



The only species closely allied to this is D. dormant, but in that 

 the spire is more conic. The name totonacus is derived from the 

 name of the tribe of the Totonacs, that dwell in the district of Mis- 

 antla. 



D. DOMINICUS Reeve. (See p. 3.) 



Callejon de la Zamora, near Vera Cruz (Strebel); Mirador and 

 Tabasco (Berendt); Chiapas (Ghiesbreght); Labna, Yucatan (Heil- 

 prin Exped.); San Nicolas, central Nicaragua (Tate). 



D. ALBOSTRIATUS (Strebel). PI. 12, figs. 25, 26. 



In most respects so similar to D. dominicus that only its differen- 

 tial characters need be stated. The shell is only slightly shining, 

 light horn-color, and has separated, rather wide, whitish growth- 

 streaks shading out on both sides. Apex brownish horn-color; be- 

 tween the 2d and 4th whorls three narrow dark brown bands appear, 

 mostly interrupted and crossed by brown longitudinal streaks, form- 

 ing an irregular marking quite similar to that of B. heterogeneus. 

 The sculpture does not differ, and of the structure and form of the 

 whorls it is only to be said that the basal half of the last whorl is 

 sometimes darker colored. There is on the inner margin of the peri- 

 stome a rather strongly thickened whitish streak, showing the whit- 



