CUBAN ANNUIJARIIDAE TORRE AJND BARTSCH 211 



has 181. This specimen has a little over 3 whorls remaining and 

 measures: Length, 11.7 mm.; greater diameter, 8.8 mm.; lesser 

 diameter, 6.7 mm. Figure 9 of plate 17 is from a photograph of the 

 type of 0. (0.) b. semiapertum Torre and Henderson. 



OPISTHOSIPHON (CUBITASIPHONA) BERKYI TRANSITORIUM Torre and Henderson 



Plate 17, Figure 6 



1921. Opisthosiphon (Opisthosiphona) parcdonense transitorium Torre and 

 Henderson, Proc. U. S. Nat. Mus., vol. 59, p. 251, pi. 39, figs. 1, 2. 



This subspecies was described from the south entrance of Paso de la 

 Guanaja, Cubitas Mountains. Bartsch made an enormous collection 

 of this race in various stations in this pass. It is easily differentiated 

 from typical 0. {C.) berryi herryi by its smaller size and by its much 

 finer ribbing. 



The type, U.S.N.M. No. 314947, has 76 axial ribs on the first of the 

 remaining turns and 188 on the last. It has a little more than 3 whorls 

 remaining and measures: Length, 11.3 mm.; greater diameter, 8.5 

 mm.; lesser diameter, 6.4 mm. 



OPISTHOSIPHON (CUBITASIPHONA) TERSUM Torre and Henderson 



Plate 17, Figures 2, 4 



1921. Opisthosiphon (Opisthosiphona) bioscai tersum Torre and Henderson, 

 Proc. U.S. Nat. Mus., vol. 59, p. 256. 



Shell elongate-ovate, flesh colored with a yellowish tinge, marked by 

 interrupted spiral bands of brown, which are almost continuous; the 

 interior of the aperture flesh colored, rayed by the spiral bands; 

 peristome white. Nuclear whorls 2, small, well rounded, microscopi- 

 cally granulose, except for the last portion of the last turn, which shows 

 the beginning of the postnuclear axial sculpture. Postnuclear whorls 

 strongly rounded, marked by slender, retractively slanting axial 

 riblets which are distantly spaced on the first of the remaining turns 

 and which gradually become more closely approximated; on the last 

 whorl they are separated by spaces a little narrower than the riblets. 

 In the type 74 of these riblets occur upon the flrst turn, 112 upon 

 the second, and 184 upon the last; they extend prominently up on the 

 summit where, at more or less regular intervals, several of them 

 become fused to form hollow cusps that crenulate the summit. These 

 cusps are much more conspicuous on the last whorl than on the 

 earlier turns. Suture moderately constricted. Periphery strongly 

 rounded. Base moderately long, openly umbllicated, marked by the 

 continuation of the axial riblets, and by slender spiral threads within 

 the umbflicus, with a few obsolete ones immediately adjacent to it. 

 These spiral threads cause the riblets to become only slightly expanded 

 at their junction. Aperture broadly oval; peristome double, the outer 



223580—40 6 



