6 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



Spiral sculpture present on entire shell. 

 Axial ribs vertebrated. 



Axial ribs forming false but not fused tufts at 



summit Articulipoma 



Axial ribs not forming false tufts at 



summit Lindenipoma 



Axial ribs not vertebrated Chondropoma 



Wetmorepoma, new subgenus 



This subgenus is here proposed for Chondropoma (Chondropomium) 

 wctmorei Bartsch.^ In this the axial riblets are obsolete on the spire, 

 becoming a little stronger on the base and umbilical wall ; the spiral 

 sculpture is obsolete everywhere except for a slender thread marking 

 the outer limit of the umbilicus. 



The subgenus so far is known only from Beata Island, Dominican 

 Republic. 



CHONDBOPOMA (WETMOBEPOMA) WETMOBEI Bartsch 



Plate 1, Figure 3 



1932. Chondropoma (Chondropomium) weimorei Bartsch, Proc. U. S. Nat. Mus., 

 vol. 81, art. 6, p. 2, pi. 1, figs. 8, 10. 



Shell small, elongate-conic, semitranslucent, flesh-colored, with four 

 interrupted series of brown spots, which are arranged both in axial and 

 spiral order. The spaces that separate these spots axially are about equal 

 to the length of the spots, while the spaces that separate them spirally 

 are more than twice the width of the spots. The early whorls are ex- 

 ceedingly thin, permitting the columella to be seen within. They are 

 strongly rounded and marked by retractively slanting incremental lines 

 only. The succeeding turns are also thin, but less so than the early 

 whorls, and on these the incremental lines become strengthened; there 

 are also obsolete spiral threads present, which give to the general sur- 

 face a slightly malleated appearance. The suture is well constricted ; the 

 periphery of the last whorl is well rounded. The base is short and 

 strongly rounded, narrowly umbilicated, and marked by the continuation 

 of the axial lines, which here assume almost the strength of riblets 

 and a spiral thread making the outer extremity of the umbilicus. Aper- 

 ture oval; peristome simple and thin, not expanded. 



The type (U.S.N.M. No. 4o3886) has 4 whorls remaining and meas- 

 ures : Height, 9.7 mm. ; diameter, 4.3 mm. 



The nuclear whorls were described from a young specimen having 

 a little more than 5 whorls, of which the last shows the spotting de- 

 scribed in the type, the preceding ones being bluish white. I have figured 

 both specimens. 



•Proc. U. S. Nat. Mus., vol. 81, art. 6, p. 2, pi. 1, figs. 8, 10, 1932. 



