90 BULLETIN 181, UNITED STATES NATIONAL MUSEUM 



An additional specimen from the same locality is considerably 

 larger. It has 4.8 whorls and measures: Height, 15.2 mm.; greater 

 diameter, 21.6 mm. ; lesser diameter, 16.0 mm. 



PTYCHOCOCHLIS ZIGZAG (Chitty) 



Plate 14, Figures 13-15 



1857. Cyclotus zigzag Chitty, Proc. Zool. Soc. London, vol. 25, p. 150. 

 1898. Neocyclotus (Plectocijclotus) zigzag Kobelt and Mollendokff, Nacnro. 

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



Shell of medium size, depressed-helicoid. All our specimens have 

 lost the epidermis, the remaining shell being soiled white. The nu- 

 cleus consists of a little more than a single well-rounded, smooth turn. 

 Postnuclear whorls strongly rounded; the first is marked by feeble, 

 rather distantly spaced axial riblets. On the succeeding postnuclear 

 whorls the axial riblets become rather irregular, owing to the nodula- 

 tions; they also become stronger and appear almost lamellose. Be- 

 ginning with the second postnuclear whorl, nodular ridges make their 

 appearance. These ridges are not so wide as the spaces that separate 

 them and do not extend over the posterior fourth of the turns. They 

 are decidedly obliquely protractively curved. They become obsolete 

 on the last fourth of the last whorl. Suture well impressed. Pe- 

 riphery well rounded. Base openly umbilicated, strongly rounded, 

 provided with a very strong keel marking the outer limit of the 

 umbilicus. This keel is decidedly inpinched on the umbilical side, 

 and a little less so on the outside. The first half of the last turn of 

 the base is strongly nodulose; on the latter part the nodulation be- 

 comes enfeebled. The umbilical wall bears numerous axial riblets and 

 fine hairlike incremental lines. Aperture circular, oblique, protracted 

 into a slight angle at the posterior angle. Peristome thin on the 

 outer lip and thickened on the inner. Operculum typically 

 ptychocochlid. 



The specimen figured, U.S.N.M. No. 399500, is one of a series col- 

 lected by C. R. Orcutt in Grays Valley, Trelawny Parish, Jamaica. It 

 has 4.5 whorls and measures: Height, 12.4 mm.; greater diameter, 

 18.2 mm. ; lesser diameter, 13.8 mm. 



We have this species from quite a number of localities, all of which 

 are located on the northern rim of Trelawny and the western portion 

 of St. Ann Parishes. 



PTYCHOCOCHLIS SHAWAE, new species 



PluVte 14, Figures 10-12 



Shell of medium size, helicoid. The nuclear whorls and first post- 

 nuclear turn pale, the succeeding turns chestnut-brown, gradually 

 becoming paler on the last whorl. Base a little paler than the spire. 

 Aperture soiled white with a brownish tinge. The nucleus consists 



