122 BULLOETIN 181, UNITE© STATES N1ATT0[N1AIL IMTJSETJM 



umbilicus. The base is marked by obsolete nodulations and pittings. 

 The umbilical wall is marked by numerous, irregular incremental 

 lines. Aperture subcircular, protracted into an acute angle at the 

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

 thickened. The operculum has the outer edge of the lamella decidedly 

 expanded, approximating that of the succeeding turn. 



The type, U.S.N.M. No. 378167, is one of a large series of almost 

 all dead shells, collected by Orcutt at the western end of the Essing- 

 ton Bridge, St. Thomas Parish, Jamaica. It has 4.6 whorls and 

 measures : Height, 14.0 mm. ; greater diameter, 20.0 mm. ; lesser diam- 

 eter, 15.2 mm. 



Charles K. Orcutt also collected specimens near Yallahs Bay, St. 

 Thomas Parish. 



POTERIA (CYCLOBAKERIA) NOTATIOR (Chitty) 



Plate 17, Figukes 13-15 



1857. Cyclotns notafior Chitty, Proc. Zool. Soc. London, vol. 25, p. 148. 

 1899. Neocj/clotus (Plectocyclotus) notatior Kobelt and Mollendoeff, Nachrb. 

 deutschen malak. Ges., vol. 31, p. 136. 



Shell of medium size, rather elevated helicoid, wood brown. The 

 nucleus consists of a little more than a single low, rounded turn. The 

 postnuclear whorls are decidedly inflated and marked by retractively 

 curved, hairlike, closely spaced axial riblets, which become irregu- 

 larly disposed on the nodulose whorls. Beginning with the fourth 

 postnuclear whorl, feeble nodulations make their appearance, which 

 increase in size as the shell advances in growth. On the last whorl 

 they assume first a retractive slant on the posterior portion near 

 the summit, then they make a sudden protractive bend, but owing 

 to the irregular development of these cords they have a zigzag ap- 

 pearance. These cords are not quite so wide as the spaces that 

 separate them. On the last two-tenths of the last whorl they again 

 fade out. Suture strongly impressed on all but the last whorl, which 

 is decidedly appressed to the preceding turn. There is an impressed 

 area below this appressed portion which renders that part of the 

 shell slightly concave. Periphery well rounded and marked by the 

 feeble continuation of the axial sculpture. Base inflated, strongly 

 rounded, very narrowly umbilicated, and marked with a weak keel 

 at the outer edge of the umbilicus. The base is marked by incre- 

 mental lines and obsolete spiral striations. The umbilical wall bears 

 many slender axial riblets. Aperture subcircular, decidedly oblique 

 and decidedly protracted at the posterior angle. Outer lip thin and 

 sharp at the edge ; inner lip somewhat thicker. Operculum typically 

 cvclobakerid. 



