THE CYOLOPHORID LAND MOLLUSKS OF AMERICA 101 



PTYCHOCOCHLIS MAGNA (Chitty) 



Plate 15, Figures 30-32 



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



1912. Neocyclotus (Plectocyclotus) varians knobbei Kobei.t, Martini-Chemnitz 



Conchylien Cabinet, vol. 1, sect. 19, pt. 3, p. 944, pi. 141, figs. 13-14. 



Shell rather large, helicoid, pale brown with a rosy flush ; interior 

 of the aperture pale brown. The nucleus consists of a single well- 

 rounded, smooth turn. The postnuclear whorls are decidedly in- 

 flated, strongly rounded; the first is marked by slender, hairlike, 

 slightly retractively curved axial riblets. From there on oblique, re- 

 tractively slanting ridges make their appearance. These ridges extend 

 from near the summit to about the middle of the whorl; they then 

 suddenly change to a decidedly oblique protracted slant, thus produc- 

 ing a series of more or less regular cone-in-cone shaped areas. On the 

 last whorl this sculpture is replaced by rather irregular wrinkling on 

 its first half, while the last half lacks nodulations. Suture strongly 

 impressed except on the last whorl, which is appressed to the preceding 

 turn. Periphery strongly rounded. Base narrowly umbilicated, with 

 a strong keel marking the outer limit of the umbilicus. The base, as 

 well as the last part of the upper surface, shows weak spiral threads. 

 The umbilical wall is marked by rather coarse riblets and incremental 

 lines. Aperture circular, angulated at the posterior angle; outer lip 

 thin, the iimer lip thicker. Operculum typically ptychocochlid. 



The specimen figured, U.S.N.M. No. 535971, is one of three in our 

 collection labeled "Jamaica," without specific locality. It has 5 whorls 

 and measures: Height, 21.0 mm.; greater diameter, 23.9 mm.; lesser 

 diameter, 18.4 mm. 



P. magna is easily distinguished from the other members of the 

 genus by its extremely elevated outline. 



PTYCHOCOCHLIS MONTEGOENSIS, new species 



Plate 15, Figures 33-35 



Shell moderately large, depressed-helicoid, chestnut-brown. Early 

 whorls with a rosy flush. The nucleus consists of a little more than a 

 single whorl, which is well rounded and smooth. The postnuclear 

 whorls are inflated, well rounded ; the first half of the first postnuclear 

 whorl is marked by slender, slightly retractively curved axial riblets ; 

 the second half shows the beginning of decidedly protractively curved 

 wrinkles, which do not quite extend to the summit, and which are about 

 as wide as the spaces that separate them. On the penultimate whorl 

 these wrinkles take a retractive slant on the posterior portion of the 

 whorl, then bend strongly into a protractive position, thus forming 

 arrow-points that give to the sculpture of this whorl a cone-in-cone 



