54 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



CHONDBOPOMA (CHONDBOPOMA) GONAVENSE, new species 



Shell ovate, flesh-colored, with interrupted spiral bands of brown. 

 These consist of distantly spaced spots, which are also arranged in axial 

 series and really give the shell more of an axially marked pattern than 

 a spiral one. Nuclear whorls about 2, strongly rounded, smooth, forming 

 a rather slender apex. The postnuclear whorls are inflated, strongly 

 rounded, and marked by numerous retractively slanting, slender axial 

 riblets and equally numerous spiral threads; the spacing of these two 

 elements, being about equal, forms an exceedingly regular fenestrated 

 pattern. The junctions of the axial ribs and spiral threads form rounded 

 tubercles, which give to the surface a filelike aspect. The summit of the 

 whorls is narrowly shouldered and gives to the suture a slightly chan- 

 neled appearance. Periphery of the whorls inflated, strongly rounded, 

 and marked like the spire. The base is moderately long, inflated, strongly 

 rounded, and also marked like the spire except on the umbilical wall, 

 where the spiral threads assume almost the strength of cords, while the 

 axial riblets become even a little more slender and more concentrated. 

 Aperture very broadly oval, almost subcircular. Peristome double; the 

 outer very broadly flaringly expanded and adnate to the preceding turn 

 on the parietal wall, marked by feeble concentric laminae; the inner 

 is moderately exserted and reflected over about one-third of the outer 

 to which it is adnate. Operculum thin, paucispiral, with the nucleus 

 halfway between marginal and subcentral. The outer surface is covered 

 with a thin deposit of calcareous granules. 



This species ranges over the territory north of the Cul-de-Sac to 

 L'Arcahaie and Gonave Island, Haiti. It breaks up into several subspecies 

 which the key and additional diagnosis will dififerentiate. 



KEY TO THE SUBSPECIES OF CHONDROPOMA (CHONDROPOMA) GONAVENSE 



Shell very strongly inflated. 



Length more than 19 mm finitimum 



Length less than 18 mm arcahaiense 



Shell not strongly inflated gonavense 



CHONDBOPOMA (CHONDBOPOMA) GONAVENSE FINmMTJM, new subspecies 



Plate 10, Figure 4 



This race is the largest one of the group we collected on the north- 

 western rim of the Cul-de-Sac, north of Port-au-Prince. It diflfers from 

 Chondropoma (Chondropoma) gonavense gonavense by its much larger 

 size and much more inflated whorls and the much more closely spaced 

 granulations and the lack of raying of the outer peristome. In all these 

 cliaracters it agrees with Chondropoma (Chondropoma) gonavense ar- 

 cahaiense, from which its much larger size will easily differentiate it. 



The type (U.S.N.M. No. 493300) has a little more than 4 whorls re- 

 maining and measures : Length, 20 mm. ; greater diameter, 14 mm. ; 

 lesser diameter, 1 1 mm. 



U.S.N.M. No. 493301 contains 9 topotypes from the same source. 



