142 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



outer edge is more strongly reflected. The lamella is marked by retrac- 

 tively curved axial riblets. 



The chief distinction between this and Rolleia martensi is that it has 

 much fewer and more distantly spaced axial ribs. 



The type (U.S.N.M. No. 504088) was collected by E. C. Leonard at 

 Ennery, Haiti. It has 4.5 whorls and measures: Height, 5.5 mm. ; 

 greater diameter, 12.0 mm. ; lesser diameter, 8.0 mm. 



U.S.N.M. No. 364037 contains 112 topotypes from the same source, 

 some of which are considerably larger than the specimens used as the 

 type. One of these has a diameter of 15 mm. 



U.S.N.M. No. 366783 contains i specimen collected by Leonard in 

 moss on the mountain summit between Ennery and San Michel. 



U.S.N.M. No. 393778 contains 4 specimens collected by Bartsch 14 

 miles north of Gonai'ves. 



U.S.N.M. No. 393783 contains 3 specimens collected by Bartsch 15 

 miles north of Gonai'ves. 



U.S.N.M. No. 393801 contains 4 specimens collected by Bartsch on 

 Peterborough Mountain. 



LAGOPOMA, new genus 



Shell helicoid, whorls strongly rounded, marked by axial ribs and 

 spiral threads, the junction of which produces granules. Base openly 

 umbilicated. The sculpture of the spire extends over the base and into the 

 umbilicus. Aperture subcircular; peristome double, the outer broadly 

 expanded with a deep notch at the posterior termination of the inner lip. 

 Posterior to this notch the broadly expanded peristome curls inwardly 

 to produce a tubular effect. Operculum with subcentral nucleus, bearing 

 a decidedly elevated, thin lamella, which is almost vertical in its basal 

 two-thirds, then bending outward. It is marked by fine, retractively slant- 

 ing lines. 



Type species : Lagopoma lagopoma, new species. 



liAGOPOMA LAGOPOMA, new species 



Plate 23, Figures 1-3 



Shell helicoid, pale brown, with brown rays on the expanded peri- 

 stome; the apical whorls are frequently reddish. Nuclear whorls 1.6, well 

 rounded, minutely granulose. Postnuclear whorls strongly rounded, 

 marked by slightly retractively curved axial riblets and spiral cords; 

 of the latter 12 are present on the last whorl between the summit and the 

 periphery, and ii on the preceding turn. The junction of the axial ribs 

 and spiral threads forms almost rounded nodules. Suture slightly chan- 

 neled. Periphery strongly rounded. Base decidedly openly umbilicated, 

 marked by the continuation of the axial ribs and nine spiral cords be- 

 tween the periphery and the edge of the umbilicus. The umbilical wall 



