100 BULLETIN 181, UNITED STATES NATIONAL MUSEUM 



The base is marked by incremental lines and appears free from nodu- 

 lations. The umbilical wall is marked by coarse, irregular riblets 

 and lines of growth. Aperture circular, decidedly oblique, with a 

 strongly protracted angle at the posterior angle; outer lip thin; 

 the inner, thickened. Operculum typically ptychocochlid. 



The type, U.S.N.M. No. 395588, was collected by Orcutt at Arntully 

 Estate on Stony Valley River, at an elevation of 3,000 feet in St. 

 Thomas Parish, Jamaica. It has 5.1 whorls and measures : Height, 

 20.1 mm. ; greater diameter, 26.8 mm. ; lesser diameter, 20.0 mm. 



The species appears to range through the southern slope of the Blue 

 Mountains in St. Thomas Parish. 



PTYCHOCOCHLIS MINOR (Chitty) 



Plate 15, Figube.s 10-12 

 1857. Cyclotus corrugatior minor Chittt, Proc. Zool. Soc. London, vol, 25, p. 150. 



Shell of medium size, depressed-helicoid, covered with a pale brown 

 periostracum. The nucleus consists of a little more than a smooth 

 rounded whorl. The postnuclear whorls are inflated and well rounded ; 

 the first is marked by slender, very poorly developed axial riblets. Be- 

 ginning with the second, these axial riblets form wrinkles, which do 

 not extend to the summit of the whorls but are decidedly obliquely 

 protractively slanting on the posterior half of the whorl, and then 

 bend at an equal angle, retractively, toward the suture, that is, form- 

 ing an arrow-shaped angle, producing a cone-in-cone effect. The 

 spaces that separate these wrinkles are not quite so wide as the wrinkles. 

 This sculpture disappears on the last whorl, where irregularly de- 

 veloped and distributed nodules replace it. Suture well impressed on 

 the early whorls ; on the last whorl the summit is appressed and the 

 suture becomes less conspicuous. Periphery well-rounded. Base well 

 rounded, rather narrowly umbilicated, with a strong keel marking the 

 outer edge of the umbilicus, which is decidedly pinched in at its inner 

 margin. The outside of the umbilical keel is rendered notched by the 

 irregularly developed incremental lines. The rest of the base is 

 marked by obsolete spiral threads. The umbilical wall bears rather 

 coarse, closely spaced riblets. Aperture subcircular, oblique, de- 

 cidedly protracted into an angle at the posterior angle; outer lip thin, 

 inner lip somewhat thickened. Operculum typically ptychocochlid. 



The specimen figured, U.S.N.M. No. 128016, comes from Mandeville, 

 Manchester Parish, Jamaica. It has 4.5 whorls and measures: 

 Height, 12.5 mm. ; greater diameter, 17.8 mm. ; lesser diameter, 13.3 mm. 



Tliis species appears to range through southwestern Manchester 

 Parish and southeastern St. Elizabeth Parish. 



