184 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



approximated on the later whorls. These riblets at irregular intervals 

 form small, more or less rounded, white, hollow cusps at the summit. 

 The intercostal spaces are marked by microscopic axial hairlines. 

 Suture well constricted. Periphery decidedly inflated, well rounded. 

 Base short, inflated, well rounded, openly umbilicated, and marked 

 by the continuation of the axial ribs and by a series of low equal spiral 

 threads within the umbilicus. The last whorl is solute for about 

 one-fifth of a turn, the outer peristome of the parietal wall sometimes 

 touching the preceding whorl. Aperture broadly ovate; peristome 

 double, the inner exserted, reflected, and appressed to the outer lip, 

 free on the inner lip; the outer peristome is narrow on the outer lip 

 and decidedly expanded on the inner and parietal wall. There is a 

 deep notch on the inner lip, posterior to which the peristome is reflected 

 over the umbilicus, wliich it partially shields. Operculum typically 

 opisthosiphonid. Siphon behind the posterior angle of the aperture 

 directed backward and free. 



The species appears restricted to the western end of the Cubitas 

 Alountains. We are recognizing two subspecies, which the following 

 key and descriptions will differentiate: 



KEY ro THE SUBSPECIES OF OPISTHOSIPHON (BERMUDEZSIPHONA) SUBOBTURATUM 



Shell ovate subobturatum 



Shell very broadly ovate tinajaense 



OPISTHOSIPHON (BERMUDEZSIPHONA) SUBOBTURATUM SUBOBTURATUM 

 Torre and Henderson 



Plate 13, Figure 8 



1920. Opisthosiphon (Opisthosiphona) subobturatiis Henderson and Bartsch, 



Proc. U. S. Nat. Mus., vol. 58, p. 67, MS. 



1921. Opisthosiphon (Opisthosiphona) obturatum subobturatum Torre and Hen- 



derson, Proc. U. S. Nat. Mus., vol. 59, p. 253, pi. 39, figs. 7-11. 



This race was collected by Torre, Henderson, and Simpson in the 

 Paso de las Trincheras, in a cave known as Los Indios, Camagiiey 

 Province. It is distinguished from 0. (B.) subobturatum tinajaense in 

 being much less rotund ; that is, it is more elongate-ovate and is nearer 

 unicolor. The type has 34 axial ribs on the first of the remaining 

 turns and 130 on the last. 



The type, U.S.N.M. No. 314949, has a little more than 4 whorls 

 remaining and measures: Length, 13.5 mm.; greater diameter, 9.2 

 mm.; lesser diameter, 6.9 mm. 



OPISTHOSIPHON (BERMUDEZSIPHONA) SUBOBTURATUM TINAJAENSE. new subspecies 



Plate 13, Figure 13 



This race was coHected in large numbers at many stations in Paso 

 de la Tinaja, Cubitas Mountains, the pass west of Trincheras, Cama- 

 giiey Province, It is distinguished from 0. (B.) subobturatum sub- 

 obturatum by its more rotund shape and by its much more conspic- 



