10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



Imdly worn that no remarks about their sculpture can be made. 

 Furthermore, part is broken away to show that a plug has already 

 been formed in the interior, indicating where decollation is to take 

 place. The remaining whorls are inflated and strongly rounded and 

 are crossed by incremental lines of varying strength, some of which, 

 not regularly spaced, assume almost the strength of threads. In addi- 

 tion to these, more or less regularly distributed incised microscopic 

 spiral lines and obsolete lirations are present. Suture strongly con- 

 stricted ; i^eriphery inflated and well rounded ; base narrowly uni- 

 bilicated, having the same sculpture as the spire. The last whorl is 

 provided with a very heavy callus, slightly behind the peristome, 

 which might be called a varix. Aperture very oblique, irregularly 

 ovate, ex]mnded at the outer edge and appressed and adnate to the 

 base of the preceding turn at the parietal wall. The operculum is 

 thin, horny, and has 2.2 whorls. In the radula the rachidian tooth 

 has a strong median cusp, a lesser one adjoining this and a feeble 

 one outside of it. The basals are 4 in number on each side and de- 

 crease in size from the inner outwardly, the outer one being poorly 



developed, the formula being — — - . I'he lateral has a very large 



cusp and 2 lesser ones on the inside of this, and 4 on the outside, 

 the fourth being feebly developed. The innner marginal bears 7 

 denticles and the outer 6. 



Adams' type, U.S.N.M. no. 21 188, measures: Height, 7.1 mm, 

 diameter, 4.2 mm. This has the outer lip partly fractured. I have 

 therefore, in addition to this, figured another typical specimen from 

 the type locality, U.S.N.M. no. 175797, which has 4.3 whorls remain- 

 ing and measures : Height, y.2 mm, diameter, 4.6 mm. 



The additional specimens in our collection yield th.e following 

 measurements : 



U.S.N.M. no. 21188. 

 U.S.N.M. no. 175797 



