214 PROCEEDINGS OF THE NATIONAL, MUSEUM Vol.89 



inflated, strongly rounded, marked by the continuation of the axial 

 ribs and by numerous spu'al lirations on the umbilical wall. The last 

 whorl is solute for a fraction of a turn and has a strong carina behind 

 the posterior angle of the aperture, where the reflexed breathing siphon 

 forms a conspicuous element. Aperture oval; peristome double, the 

 inner peristome slightly exserted; the outer usually a little wider on 

 the parietal wall and the inner lip than on the outer lip, forming a 

 conspicuous auricle at the posterior angle, which is appressed to the 

 breathing siphon. Operculum typically opisthosiphonid . 



This species occupies the Cubitas Mountain range of Camagiiey 

 Province, where it breaks up into the two following subspecies : 



KEY TO THE SUBSPECIES OP OPISTHOSIPHON (CUBITASIPHONA) PAREDONENSE 



Whorls strongly inflated escalerense 



Whorls not strongly inflated paredonense 



OPISTHOSIPHON (CUBITASIPHONA) PAREDONENSE ESCALERENSE, new subspecies 



Plate 17, Figure 3 



This race was collected by Bartsch in large numbers on Paso de la 

 Escalera. It is larger than the typical race and has the whorls 

 much more inflated and the axial ribs on the early turns much less 

 numerous; it is only upon the last whorl that these ribs become de- 

 cidedly concentrated. 



The type, U.S.N.M. No. 535479, has 33 axial ribs on the first of the 

 remaining turns and 175 are on the last. It has almost 4 whorls 

 remaining and measures: Length, 12.5 mm.; greater diameter, 8.7 

 mm. ; lesser diameter, 6.5 mm. 



OPISTHOSIPHON (CUBITASIPHONA) PAKEDONENSE PAREDONENSE Torre and 



Henderson 



Plate 17, Figure 5 



1920. Opisthosiphon (Opisthosiphona) parcdonensis (Torre and Henderson) Hen- 



derson and Bartsch, Proc. U. S. Nat. Mus., vol. 58, p. 67, nomen nudum. 



1921. Opisthosiphon (Opisthosiphona) paredonense paredonense Torre and Hen- 



derson, Proc. U. S. Nat. Mus., vol. 59, p. 251, pi. 38, figs. 9-11. 



This race, which is remarkably abundant in the Paso de los Pare- 

 dones, Cubitas Mountains, is distinguished from 0. (C.) p. escalerense 

 by its smaller size and by its much less inflated whorls, with the ribs 

 more closely spaced on the second whorl. The cusps at the summit 

 are also much more pronounced. 



The type, U.S.N.M. No. 314946, has 62 axial ribs on the first of 

 the remaining turns and 156 on the last; it has a little over 4 whorls 

 remaining and measures: Length, 12.5 mm.; greater diameter, 8.4 

 mm.; lesser diameter, 6.3 mm. 



