194 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



Base strongly rounded, with closed umbilicus, marked by the con- 

 tinuation of the axial ribs and by several spiral threads within the 

 umbilicus. Last whorl adnate to the preceding turn. Aperture 

 broadly oval; peristome double, the inner slightly exserted and re- 

 flected; the outer broadly expanded and reflected, somewhat sinuous, 

 marked by concentric lamellae, notched on the middle of the inner 

 lip, the part posterior to the notch reflected over the umbilicus, which 

 it closes. Operculum typically opisthosiphonid, rather large — too 

 large to be withdrawn within the aperture. Siphon at the posterior 

 angle of the aperture directed backward into the suture, from which 

 it communicates by a channel behind the parietal outer lip with the 

 umbilicus, the hollow axis, and the decollated tip. 



We are recognizing three subspecies, all from the Isle of Pines, 

 which the following key and descriptions will help to differentiate: 



KEY TO THE SUBSPECIES OF OPISTHOSIPHON (OPISTHOSIPHONA) PUPOIDES 



Suture decidedly channeled pupoides 



Suture not decidedly channeled. 



Axial ribs of last whorl very closely spaced velazquezi 



Axial ribs of last whorl not very closely spaced bibijaguaense 



OPISTHOSIPHON (OPISTHOSIPHONA) PUPOIDES PUPOIDES, new subspecies 



Plate 15, Figure 4 



1849. Cyclosloma pupoides Morelet, Testacea novissima insulae Cubana et 



Americae Centralis, p. 23. 

 1852. Tudora pupoides Pfeiffer, Catalogue of Phaneropneumona ... in the 



British Museum, p. 180. 

 1920. Opisthosiphon (Opisthosiphona) pupoides Henderson and Bartsch, Proc. 



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



Bartsch collected this subspecies in large numbers at many stations 

 in the Sierra de Casas. It closely resembles typical 0. (0.) pupoides 

 velazquezi but may be differentiated by the deeply channeled suture. 



The specimen figured, U.S.N.M. No. 535467, came from the south 

 end of the west side of the Sierra de Casas, It has 44 axial ribs on the 

 first remaining postnuclear whorl and 112 on the last; it has 7.0 whorls 

 remaining and measures: Length, 17.8 mm.; greater diameter, 9.5 

 mm.; lesser diameter, 7.0 mm. 



OPISTHOSIPHON (OPISTHOSIPHONA) PUPOIDES VELAZQUEZI, new subspecies 



Plate 15, Figure 6 



We have seen this subspecies from many stations in the Sierra de 

 Caballos. It is differentiated from 0. (0.) pupoides casasense in 

 having the suture not conspicuously channeled, with the outer 

 peristome more strongly, obliquely reflected. 



The type figured, U.S.N.M. No. 392000, is one of a series collected 

 by Bartsch. It has 27 axial ribs on the first whorl and 147 on the last; 



