196 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



OPISTHOSIPHON (OPISTHOSIPHONA) MORELETIANUM COLUMBENSE, new subspecies 



Plate 15, Figure 5 



This subspecies was collected by Bartsch at the Mogote Columbia, 

 a limestone block southeast of the Sierra de Caballos. It differs from 

 the typical 0. (0.) moreletianum moreletianum in being much smaller 

 and in having the axial ribs much more closely approximated. 



In the type, U. S. N.M. No. 535468, the first postnuclear whorl has 

 30 axial ribs, while the last has 102. This is a complete specimen 

 having 6 whorls and measuring: Length, 12.5 mm.; greater diameter, 

 7.2 mm.; lesser diameter, 5.3 mm. 



opisthosiphon (opisthosiphona) moreletianum moreletianum (petit) 



Plate 15, Figure 2 



1849. Cyclostoma disjunclam Morelet, Testacea novissima insulae Cubana 



et Americae Centralis, p. 23. Not Cyclostoma disjunctum Matheron, 

 Ann. Sci. Midi France, vol. 3, p. 59, 1832. 



1850. Cyclostoma moreletiana Petit, Journ. Conchyl., vol. 1, p. 46, February 15. 

 1850. Cyclostoma moreleii Pfeiffer, Zeitschr. MalakozooL, vol. 7, pp. 88-89, 



August. 

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



British Museum, p. 180. 

 1920. Opisthosiphon (Opisthosiphona) moreletiana Henderson and Bartsch, 



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



The typical race comes from the Sierra de Casas where we found it 

 on both the northern and southern half. It is differentiated from 

 0. (0.) moreletianum columbense in being larger and in having the 

 axial ribs more distantly spaced. 



The specimen figured, U.S.N.M. No. 391711, has 35 axial ribs on 

 the first postnuclear whorl and 71 on the last turn. It is a complete 

 specimen of 6.8 whorls and measures: Length, 14.0 mm.; greater 

 diameter, 8.2 mm. ; lesser diameter, 5.7 mm. 



The shell grows considerably larger than this, but we selected it 

 because it was nearly complete. A specimen having 5 whorls remain- 

 ing measures: Length, 17.3 mm.; greater diameter, 10.2 mm.; lesser 

 diameter, 7.0 mm, 



OPISTHOSIPHON (OPISTHOSIPHONA) PLICATUM, new species 



Plate 15, Figure 1 



Shell elongate-ovate, thin, pale brown with interrupted spiral bands 

 of darker brown. Nuclear whorls almost 2, strongly inflated and well 

 rounded, microscopically granulose, forming a truncated apex. The 

 last of the nuclear tm'ns shows the beginning of the postnuclear 

 sculpture. Postnuclear whorls inflated, strongly rounded, and marked 

 by retractively ciu-ved axial ribs, which are sublamellar on the early 

 turns, but which are reduced to rounded tlu-eads on the last whorl. 



