102 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



HAITIPOMA, new genus 



Shell varying from cylindroconic to elongate-ovate in outline. The 

 whorls are marked with axial ribs, which fuse into tufts at the summit. 

 The spiral sculpture is well developed ; its threads render the axial rible^s 

 weakly nodulose at their junction. The spiral threads are heavier on 

 the umbilical wall than on the spire. Suture channeled in varying de- 

 grees in the different races. Last whorl solute. Aperture oval, varyingly 

 auriculated at the posterior angle. Peristome double, the outer varying 

 greatly in the expansion of the inner lip in the different species. Oper- 

 culum with excentric nucleus, provided with strong lamellar, retrac- 

 tively curved ribs, which do not extend to the outer edge of the 

 basal chondroid plate. 



Type species : Cyclostoma amincnsis Pf eiffer = Haitipoma aminense 

 (Pfeiffer). 



This genus somewhat resembles Hispanipoma from which the double 

 peristome will at once distinguish it. 



KEY TO THE SPECIES OF HAITIPOMA 



Inner lip of outer peristome very broadly expanded. 



Shell slender catalinense 



Shell stout marcense 



Inner lip of outer peristome not very broadly expanded. 

 Shell elongate-ovate. 



Axial ribs and spiral threads distantly spaced eutyches 



Axial ribs and spiral threads not distantly spaced. 



Tufts at the summit exceedingly strong hinchense 



Tufts at the summit not exceedingly strong. 

 Axial ribs very closely spaced. 



Aperture with a strong auricle yaquense 



Aperture without a strong auricle genevievae 



Axial ribs not very closely spaced. 



Shell stout poolei 



Shell slender aminense 



Shell not elongate-ovate but cylindroconic. 



Sculpture strong cinclidodes 



Sculpture feeble abbotti 



HAITIPOMA CATAUNENSE, new species 



Plate 15, Figure 6 



Shell elongate-ovate, flesh-colored, with interrupted spiral bands of 

 pale brown, these usually occupying the spaces between the spiral cords ; 

 one band at the periphery is a little stronger than the rest. Nuclear whorls 

 almost 2, well rounded, microscopically granulose, the last whorl show- 

 ing indications of axial threads. The nuclear whorls form a truncated 

 apex. Postnuclear whorls inflated, well rounded, marked by retractively 

 slanting, sublamellar axial riblets, which become more closely approxi- 

 mated as the whorls increase in number. These riblets are of fairly 

 regular width but differ considerably in spacing. Of these riblets, 70 



