1 82 PROCEEDINGS OF THE NATIONAL, MUSEUM vol. 89 



Some of these riblets become expanded at rather regular intervals at 

 the summit, where they project as slender hollow cusps. The inter- 

 costal spaces are marked by microscopic axial threads. Suture 

 strongly constricted. Periphery strongly rounded. Base short, in- 

 flated, openly umbilicated, marked by the continuation of the axial 

 riblets and by 3 spiral threads on the edge of the umbilicus, and by 

 10 within the umbilicus. Last whorl solute for about one-eighth of 

 a turn. Aperture broadly oval; peristome double, the inner exserted 

 and slightly reflected; the outer moderately broadly expanded, a 

 little more so on the inner and the parietal wall than on the rest, 

 and reflected as a broad backward-turned auricle at the posterior 

 angle, which covers the backward-directed siphon. Operculum typi- 

 cally opisthosiphonid. 



The type, U.S.N.M. No. 314954, comes from Finca Santa Rita 

 near El Cercado, Cubitas Mountains, Camagiiey Province. It has a 

 little more than 3 whorls and measures: Length, 10.9 mm.; greater 

 diameter, 8.0 mm.; lesser diameter, 5.9 mm. 



The collection also includes a large series of specimens collected by 

 Bartsch at Finca Gertrudis, a little east of the type locality. 



OPISTHOSIPHON (BERMUDEZSIPHONA) EVANIDUM Torre and Henderson 



Shell elongate-conic, flesh colored except for the plug at the decol- 

 lated end, which is brown. Nuclear whorls decoUated. Postnuclear 

 whorls inflated, strongly rounded, and marked by slender, retrac- 

 tively curved axial riblets, which are very distantly spaced on the 

 early tm-ns and which become gradually more closely approximated. 

 On the last whorl the spaces that separate them are only about twice 

 as wide as the riblets. The intercostal spaces are marked by micro- 

 scopic axial threads. At more or less regular intervals some of these 

 riblets become expanded and thickened at the summit, where they 

 form conspicuous white hollow denticles. Suture strongly con- 

 stricted. Periphery strongly inflated, well rounded. Base short, 

 openly umbilicated, inflated, well rounded, and marked by the con- 

 tinuation of the axial riblets and feeble spiral threads on the 

 bend of the umbilicus, and by stronger spiral threads on the umbiUcal 

 wall. Last whorl solute for about one-fourth of a turn. Aperture 

 broadly oval; peristome double, the outer moderately expanded on 

 the inner lip and at the posterior angle, where it forms a conspicuous 

 auricle that is reflected over the siphon. On the outer and basal 

 lip it extends but slightly beyond the inner peristome; inner peri- 

 stome slightly exserted and reflected. Operculum typically opistho- 

 siphonid. 



The species appears to be confined to the south side of the Cubitas 

 Mountains, Camagiiey Province. 



