222 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



The subspecies is charactered by having a bright rose-colored tip, 

 with the rest of the shell faintly flushed with rose. The peristome and 

 the interior of the aperture are buff. 



The type, U.S.N.M. No. 355127, comes from Sierra de Guane. 

 It has a little more than 4 whorls remammg and measures: Length, 

 17.0 mm.; greater diameter, 11.4 mm.; lesser diameter, 8.9 mm. 



The anunal of this subspecies was collected on the Sierra de los 

 Acostas July 6, 1928, by Bartsch. He describes it as having the upper 

 parts pale buff, marbled with small brownish streaks. The sides of 

 the body are darker than the dorsum. Tentacles pale buff. Sole of 

 the foot short, flesh colored with smoky suffusion, deeply, medially 

 cleft, the motion being alternate on the two sides. 



HHYTIDOTHYRA BILABIATA NANA, new subspecies 



Plate 18, Figure 1 



This subspecies occupies the various limestone blocks surrounding 

 Kilometer 14 between Pinar del Rio and Vinales. It is a small, 

 completely white race; even the peristome is white. In the axial 

 ribbing it resembles R. bilahiata straminea, from which the color will 

 distmguish it. The spiral sculpture in nana is a little stronger, also. 



The type, U.S.N.M. No. 355136, comes from the mogote on the 

 north side of the road. It has a little more than 4 whorls remaining 

 and measures: Length, 15.0 mm.; greater diameter, 9.2 mm.; lesser 

 diameter, 7.5 mm. 



BHYTIDOTHYRA BILABIATA STRAMINEA, new subspecies 



Plate 18, Figure 3 



This subspecies ranges through the isolated blocks of limestone 

 known as Hoyo del Guamd, Las Cuevitas, and Las Lagunitas. It is a 

 medium-sized race, with the early whorls white and with the rest of 

 the shell straw-colored. The axial ribs are sublamellar and expanded 

 at the free margin. The spiral sculpture is comparatively reduced 

 so that it is not as conspicuous as in the other races. 



The type, U.S.N.M. No. 169927, comes from Hoyo del Guamd. It 

 has 3.5 whorls remaining and measures: Length, 15.1 mm.; greater 

 diameter, 10.2 mm.; lesser diameter, 8.2 mm. 



Genus XENOPOMA Crosse 



1890. Xenopoma Crosse, Journ. Conchyl., vol. 38, p. 282. 



Shell elongate-conic, with the last part of the last whorl detached 

 and deflected considerably below the preceding turn. The sculpture 

 consists of widely spaced axial ribs, which bear strong, hollow, cusplike 

 tubercles at their intersections with the obsolete spiral cords. In 

 addition to this, fine, wavy axial threads occur between the cusped 



