HISPANIOLAN AND BAHAMAN ANNULARHDAE 75 



U.S.N.M, No. 403074 contains 12 specimens collected by Orcutt south 

 of the road west of Jeremie. 



U.S.N.M. No. 40291 1 contains 155 specimens collected by Orcutt 

 east of Trou Bonbon. 



U.S.N.M. No. 402653 contains 66 specimens collected by Orcutt be- 

 tween Anse du Clerc and Trou Bonbon. 



U.S.N.M. No. 355178 contains 45 specimens collected by Dr. W. L. 

 Abbott at Moron. 



CROSSEPOMA, new genus 



Shell elongate-conic, marked by axial ribs that fuse at the summit to 

 form tufts. Spiral sculpture present in the form of threads or indicated 

 by feeble nodules on the axial ribs, always stronger on the umbilical 

 wall than on the spire. Umbilicus open. Aperture oval ; peristome simple. 

 Operculum with a heavy calcareous deposit, which is marked by retrac- 

 tively curved axial riblets, leaving, however, a space between the turns 

 showing the basal chondroid plate. 



Crossepoma is easily distinguished from Parachondrella by the strong 

 tufting of the axial ribs at the summit. In Parachondrella they remain 

 distinct. 



Type species : Cy do stoma emilianum Weinland = Crossepoma emili- 

 anum (Weinland), 



KEY TO THE SPECIES OF CROSSEPOMA 



Axial ribs distantly spaced hendersoni 



Axial ribs closely spaced. 

 Axial ribs broad. 



Shell large, height more than 15 mm emilianum 



Shell small, height less than 12 mm australe 



Axial ribs not broad jacmelense 



CROSSEPOMA HENDERSONI, new species 



Plate 13, Figure 9 



Shell elongate-conic, pale buflf, with interrupted spiral bands of brown, 

 of which six are present between summit and periphery. A very broad 

 seventh spiral band is immediately below the periphery and three 

 smaller ones are anterior to this on the base. The columella also is pale 

 brown. All these brown markings show within the aperture. There is 

 also a small brown spot at the beginning of the nuclear turns. Nuclear 

 whorls 1.5, inflated, well rounded, microscopically granulose. The ter- 

 minal portion of the nuclear whorls gradually passes into the post- 

 nuclear sculpture. The postnuclear whorls are moderately well rounded. 

 The early ones less so than the later. They are crossed by strong sub- 

 lamellar axial ribs, several of which may become fused into hollow 

 cusps at the summit, or the individual ribs may become thus expanded. 

 Of these axial ribs, 84 are present on the last turn. The spiral sculpture 

 is indicated by feeble nodulations, which are stronger on the early turns. 

 The intercostal spaces do not show spiral threads. Suture moderately 



