74 BULLOETIiN 181, UNITEO SfTATEIS NIATTOi]S[lAL MUSIEUM 



riblets radiate from the keel, leaving broad impressed pits between 

 them. These riblets do not extend over more than one-third of the 

 base; the rest of the base is marked by incremental lines and slight 

 pittings. Aperture circular, protracted into a clawlike element at the 

 posterior angle; outer lip of the peristome thin, the inner somewhat 

 thickened, particularly so at the umbilical keel. Operculum typically 

 cyclopilsbryid. 



The type, U.S.N.M. No. 535965, was collected by Orcutt on Glen- 

 burnie Mountains, Westmoreland Parish, Jamaica. It has 5.3 whorls 

 and measures : Height, 19.2 mm. ; greater diameter, 26.5 mm. ; lesser 

 diameter, 19.4 mm. 



Four additional lots from the immediate type locality are in the col- 

 lection of the National Museum. 



The profound pits outside of the umbilical keel readily distinguish 

 this species from G. (O.) ru/pisfontis (Chitty), which it most nearly 

 resembles. 



CYCLOPILSBRYA (CYCLOPILSBRYA) RUPISFONTIS (Chitty) 



Plate 12, Figures 24-26 



1857. Cydotus rupisfontis Chitty, Proc. Zool. Soc. London, vol. 25, p. 155. 

 1898. Neocyclotns (Plectocyclotus) ri/p/s/o/i^fs Kobelt and Mollendorff, Nachrb. 

 deutschen malak. Ges., vol. 29, p. 139, reprint. 



Shell of medium size, elevated helicoid, covered with a dark chest- 

 nut-brown periostracum except the region immediately below the 

 summit, which is buff. There are also frequently spiral lines of the 

 buff coloration on the last part of the last turn. The nucleus con- 

 sists of 1.3 well rounded, smooth turns. The postnuclear whorls are 

 inflated, strongly rounded; the first is marked by very regular, 

 strongly elevated axial riblets, which are separated by spaces about 

 as wide as the riblets. Beyond this turn the axial sculpture becomes 

 irregular and the riblets become more or less sinuous on the next 

 whorl, while on the last whorl they are very sinuous and the indi- 

 viduals vary materially in strength from the summit to the periphery, 

 forming in fact a series of jointed slight wrinkles. In addition to 

 this, there are heavy wrinkles on the last whorl, which are also 

 irregular and slope in a general, slightly protractive direction. They 

 are strongest on the middle of the turns and weaken toward the 

 summit and the periphery and lend to the last whorl an irregularly 

 nodulose aspect. Suture well impressed except on the last turn, 

 which creeps very strongly up on the preceding turn, to which it 

 is appressed, leaving a slight concave area below its summit. Pe- 

 riphery well rounded. Base inflated, strongly rounded, rather nar- 

 rowly umbilicated, provided with a strong keel at the outer edge of 

 the umbilicus. On the umbilical side the keel is strongly inpinched, 



