THE CYCLOPHORID LAJSJD M0LLUSK9 OF AMIERIClA 93 



ture subcirciilar, oblique, protracted to form an angle at the posterior 

 angle; peristome moderately thickened all around. Operculum 

 unknown. 



The unique type is in the C. B. Adams collection. It measures: 

 Height, 22.4 mm.; greater diameter, 33.4 mm.; lesser diameter, 26.2 

 mm. It was with Adams' No. 7 of Cyclostoma varians collected by 

 Agnes Hines in Portland Parish, Jamaica. 



PTYCHOCOCHLIS CORRUGATA (Menke) 



Plate 14, Figures 7-9 



1795. Turbo jamaicensis Chemnitz, Martini-Chemnitz Conchylien Cabinet, vol. 



11, p. 277, pi. 209, figs. 2057, 2058 (nonbinomial). 

 1830. Cyclostoma corrugatum Menke { = Turl}0 jamaicensis Chemnitz), SsTiopsis 



methodica Molluscorum, p. 39. 

 1857. Cyclotus portlandensis Chitty, Proc. Zool. Soc= London, vol. 25, p. 147. 



Shell moderately large, helicoid, chestnut-brown, a little paler on 

 the last whorl, which tends toward buff. The appressed summit of 

 the whorls is also a little paler than the rest of the shell. There is 

 a broad dark band at the periphery, while the anterior portion of 

 the base and the umbilicus are flesh colored with a yellowish tinge, 

 which is also the color of the interior of the aperture. The nucleus 

 consists of a little more than a turn, which is well rounded and 

 smooth. The postnuclear whorls are strongly rounded ; the first one 

 and three-quarters are marked by slender, decidedly elevated, and 

 rather distantly spaced, slightly protractivelj slanting axial riblets. 

 Following this, wrinkles make their appearance. These are arranged 

 in a somewhat arrow-shaped pattern extending retractively over a 

 third of the distance between the summit and the periphery, then 

 bending abruptly protractively toward the periphery. These ridges 

 are about as wide as the spaces that separate them and fade out at 

 the summit, which is appressed to the preceding turn as a ridge. 

 On the last third of the last turn these ridges become decidedly 

 irregular and gradually fade out. On the last turn there is a strong 

 depression a little distance below the summit. On all these ridged 

 whorls the fine axial riblets are well developed, but are rendered 

 irregular and wavy as they cross the nodules of the ridges. On 

 the first two turns the suture is strongly impressed ; on the succeeding 

 turn it is rendered less conspicuous by the appression of the summit 

 of the whorls to the preceding turn. Periphery well rounded. Base 

 strongly rounded, openly umbilicated, with a very pronounced keel 

 marking the outer edge of the umbilicus. This keel is separated 

 from the umbilical wall by a deeply impressed groove. On the out- 

 side it is less strongly differentiated. The posterior half of the base 

 is more or less smooth, while the anterior portion is marked by pro- 



428349 — 42- 7 



