THE CYCLOPHORID LAND MOLLUSKS OF AMERTCA 119 



POTERIA (CYCLOBAKERIA) WELCHI TAYLORI, new subspecies 



Plate 17, Figures 37-39 



This race was collected by C. B. Taylor and John B. Henderson 

 in the Great Valley, Hanover Parish, Jamaica. It is easily differenti- 

 ated from P. (C.) w. welchi by having the upper surface of the last 

 whorl obsoletely nodulose on its anterior half, and by having the 

 pits posterior to the umbilical keel very poorly indicated, and the 

 radiating ridges bordering the pits almost absent. 



The type, U.S.N.M. No. 535978, comes from Great Valley, Hanover 

 Parish, Jamaica. It has 4.9 whorls and measures : Height, 16.0 mm. ; 

 greater diameter, 23.9 mm. ; lesser diameter, 17.1 mm. 



POTERIA (CYCLOBAKERIA) MAGISTER, new name 



Plate 17, Figukes 40-42 



1857. Cyclotus cornigatus Chitty, Proc. Zool. Soc. London, vol. 25, p. 146 (not 

 Cyclostoma corrugatum Menke, Synopsis methodica moUuscorum, p. 39, 

 1830). 



Shell very large, helicoid, wood brown, a little paler on the early 

 whorls. The nucleus consists of a single well-rounded, smooth turn. 

 The postnuclear whorls are inflated, strongly rounded, and marked 

 by retractively curved axial riblets, which grow stronger as the shell 

 increases in size and less regular, owing to the nodulations. Begin- 

 ning with the fourth whorl, oblique, protractively slanting axial 

 cords make their appearance. These fade out toward the summit 

 and assume a zigzag course anteriorly ; they become decidedly weaker 

 on the last one-tenth of the last turn. Suture strongly impressed on 

 all the whorls, except the last, which is decidedly appressed to the 

 preceding turn, thus weakening the suture. Periphery well rounded, 

 crossed by the axial protractive cords. Base inflated, strongly 

 rounded, openly moderately broadly umblicated, with a strong keel a^ 

 the outer edge of the umbilicus. The keel is strongly inpinched on 

 the umbilical side and less so on the basal side. Kadiating from the 

 umbilical keel a series of strong cords about as wide as the spaces that 

 separate them extends over the anterior fourth of the base and fades 

 out toward its center. The posterior portion of the base shows the 

 feeble continuation of the zigzag cords of the spire. The umbilical 

 wall is marked by rough, closely spaced incremental threads. Aper- 

 ture subcircular, protracted at the posterior angle into a decided 

 point; outer lip thin, the inlner thickened. Operculum typically 

 cyclobakerid. 



The type is one of six specimens in the Amherst College collection, 

 labeled No. 7, collected by Chitty in Portland Parish, Jamaica. It 



