HISPANIOLAN AND BAH AM AN ANNULARIIDAE 73 



PARACHONDBI8CA UMBBICOLA (Weinland) 



Shell small, elongate-conic, brown, unicolor or with rather broad 

 spiral bands of darker brown; interior of aperture pale brown, with the 

 brown bands when present showing conspicuously. The expanded peri- 

 stome is flesh -colored. Nuclear whorls 1.5, forming a rather blunt apex, 

 strongly rounded, smooth, except for the last portion of the last turri, 

 which shows the beginning of the postnuclear sculpture. Postnuclear 

 whorls strongly rounded, marked by slender, rather distantly spaced, 

 slightly retractively slanting axial ribs. At irregular intervals these riblets 

 become expanded at the summit to form a broad, almost blisterlike 

 denticle, which is always pale in color. Suture strongly constricted, 

 almost channeled. Periphery strongly rounded. Base short, strongly 

 rounded, openly umbilicated, and marked by the continuation of the 

 axial riblets, which extend into the umbilicus where some at irregular 

 intervals become expanded into broad lamellae. These expanded ele- 

 ments are usually also stronger on the upper portion of the last whorl 

 which they render slightly varicid. There is no spiral sculpture present, 

 even on the umbilicus. Last whorl solute for about one-tenth of a turn, 

 the solute portion conspicuously angulated behind the posterior angle 

 of the aperture. Aperture subcircular; peristome double, the outer 

 broadly expanded at the posterior angle where it forms a conspicuous 

 auricle, while on the inner lip it is about half as wide as at the posterior 

 angle; on the middle of the parietal wall and the outer lip it does not 

 extend beyond the inner peristome, which is slightly exserted and re- 

 flected. Operculum typically parachondriscoid. 



KEY TO THE HISPANIOLAN SUBSPECIES OF PARACHONDRISCA UMBRICOLA 



Axial ribs fine and closely spaced cayemitensis 



Axial ribs not fine or closely spaced umbricola 



PARACHONDRISCA UMBRICOLA CAYEMITENSIS, new subspecies 



Plate 13, Figure 4 



This subspecies comes from Grande Cayemite, a large island lying 

 ofif the north coast of the south peninsula, Haiti. Its larger size and finer 

 and more closely spaced ribs, of which there are 144 on the last whorl 

 in the type, as well as the less strong tufting at the summit, will easily 

 distinguish it from typical P. u. umbricola. 



The type (U.S.N.M. No. 503997), collected by Eyerdam, has 8.4 

 whorls and measures: Length, 13.5 mm.; greater diameter, 6.1 mm.; 

 lesser diameter, 5.0 mm. 



U.S.N.M. No. 380314 contains 208 topotypes from the same source. 



PARACHONDRISCA UMBRICOLA UIVIBRICOLA (Weinland) 



Plate 13, Figure 7 

 1862. Cyclostoma umbricola Weinland, Malakozool. Blatter, vol. 9, p. iS8. 

 1865. Tudora umbricola Pfeiffer, Monographia pneumonopomorum viventium, 



Suppl. 2, p. 137. 

 1920. Parachondria (Parachondrisca) umbricola Henderson and Bartsch, Proc. 



U.S. Nat. Mus., vol. 58, p. 66. 



