CUBAN ANNUL.ARIIDAE — TORRE AND BARTSCH 177 



panded at the posterior angle to form a conspicuous auricle. It is 

 narrower on the outer and basal lip where it is again expanded on the 

 inner lip, which is deeply notched. Posterior to the notch it forms a 

 very broad flap, which extends over the umbilicus and covers it. 

 The outer peristome is marked by conspicuous concentric lamellae. 

 Operculum typically opisthosiphonid. The siphon is at the posterior 

 angle of the aperture behind the peristome, directed into the suture, 

 where it connects with the slender tube connecting with the umbilicus 

 and, through the hollow axis, with the decollated end of the shell. 

 The species is restricted to the Cubitas Mountains. We are 

 recognizing two subspecies from this locality, which the following key 

 will help to distinguish: 



KEY TO THE SUBSPECIES OF OPISTHOSIPHON (BERMUDEZSIPHONA) OBTURATUM 



Whorls inflated sulcosum 



Whorls well rounded obturatum 



OPISTHOSIPHON (BERMUDEZSIPHONA) OBTURATUM SULCOSUM, new subspecies 



Plate 13, Figure 12 



This subspecies is more elongated than 0. (B.) obturatum ohturatum. 

 It has the axial ribs on all the whorls much more distantly spaced. 

 Of these, 18 are present on the first whorl and 51 are upon the last in 

 the type. The ribs also show the nodules referred to in the specific 

 description much more emphasized than in the other subspecies. 



The type, U.S.N. M. No, 535450, was collected by Bartsch at Salto 

 del Paso Tmaja, about 1.5 km. from the north entrance to the pass. 

 It has 5.0 whorls remaining and measures: Length, 13.8 mm.; greater 

 diameter, 8.9 mm.; lesser diameter, 7.0 mm. 



OPISTHOSIPHON (BERMUDEZSIPHONA) OBTURATUM OBTURATUM Torre and 



Henderson 



Plate 13, Figure 11 



1920. Opislhosiphon {Opisthosiphona) obturatus (Torre and Henderson) Hender- 



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



1921. Opislhosiphon {Opisthosiphona) obturatum obturatum Torre and Hender- 



son, Proc. U. S. Nat. Mus., vol. 59, p. 252, pi. 39, figs. 3-6. 



This race, which comes from Paso de Lesca, Cubitas Mountains, is 

 much more rotund than 0. (B.) o. sulcosum and has broader whorls. 

 The axial ribs are much more numerous, more closely spaced, and 

 more conspicuously cusped at the summit. Of the axial ribs, 34 are 

 present on the first of the remaining turns and 92 are upon the last 

 in the type. 



The type, U.S.N.M. No. 314948, has a little more than 4 whorls 

 remaining and measures: Length, 14.5 mm.; greater diameter, 10.0 

 mm.; lesser diameter, 7.7 mm. 



