300 HELICID^. 



Shell elongated, ovate-fusiform, thin and fragUe, con- 

 siderably transparent, pale fawn color, in some specimens 

 inclined to greenish, and generally flecked with distant, 

 pale spots ; the surface is, in a measure, coarsely granu- 

 lated by the decussation of longitudinal and revolving 

 lines, the latter of which are more distant from each 

 other than the former, and become less and less distinct 

 towards the anterior portion of the whorl. Whorls seven 

 or eight, the apicial ones smooth and forming a mammil- 

 lary tip ; suture crenulated. Aperture about one-half the 

 length of the shell, nearly three times as long as broad ; 

 columella strongly arched, and scarcely glazed by ena- 

 mel. 



Length of axis two and thi'ee-fourths inches ; breadth 

 one inch. 



Geographical Distribution. Hitherto obtained 

 only in Texas and Mexico. 



Remarks. The essential distinctions between this 

 species and the preceding, are its fragile structure, its 

 reticulated surface, and its peculiar coloration. It also 

 grows to a larger size. Achatma Sowerhyana of Pfeiflfer 

 seems to be the same. It differs only in wanting the 

 white flecks. These, however, vary in amount so much 

 as to afford good reason to suppose that they are some- 

 times wanting. Its form and partially granulated sur- 

 face should rather be taken as its characteristics. — [g.] 



