32 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



shows the beginning of the postnuclear sculpture. The postnuclear 

 whorls are rather inflated, well rounded, narrowly shouldered at the 

 summit, and marked by slender, sublamellar, axial riblets, which are 

 separated by spaces about three times as wide as the riblets. These 

 riblets become somewhat thickened at the summit, which they crenulate. 

 Suture narrow, rather deeply channeled. Periphery inflated, well rounded. 

 The base is moderately long, inflated, strongly rounded, and marked by 

 the continuations of the axial ribs, which become enfeebled as they 

 enter the broadly open umbilicus. The umbilical wall is marked by well- 

 developed spiral threads, of which 13 occur on the outer half. The last 

 whorl is solute for about one-tenth of a turn, continuing the shoulder 

 as a strong carina at the posterior angle of the aperture. Aperture large, 

 oblique, broadly ovate. Peristome double, that of the outer and basal 

 lip very broadly expanded, reflected, and thickened. The peristome on the 

 parietal wall is narrow; the inner peristome is reflected over the outer 

 and appressed to it and extends over about one-half of its extent. Oper- 

 culum thin, corneous, paucispiral, with submarginal nucleus, covered 

 with a moderately thick calcareous deposit. 



The specimen figured (U.S.N.M. No. 471937) was collected by C. R. 

 Orcutt at Fond Parisien, the type locality. It has lost the early whorls; 

 the 3.5 whorls remaining measure : Length, 24.9 mm. ; greater diameter, 

 17.6 mm.; lesser diameter, 13.4 mm. 



U.S.N.M. No. 471938 contains 7 topotypes from the same source. 



U.S.N.M. No. 426041 contains a paratype from Fond Parisien, south 

 shore of fitang Saumatre. 



CHONDBOPOMA (CHONDBOPOMIUM) INAEQUILiABEUHr, new species 



Plate 5, Figure 6 



Shell ovate; nuclear whorls decollated; the early postnuclear whorls 

 brown, the succeeding turns flesh-colored, marked by broad, irregular, 

 interrupted, spiral bands of brown, the elements of which are also ar- 

 ranged in axial series. These bands extend upon the outer peristome, 

 which they ray. Nuclear whorls decollated in all our specimens. Post- 

 nuclear whorls inflated, narrowly shouldered at the summit, and marked 

 by slender, retractively curved axial riblets, which are about half as 

 wide as the spaces that separate them. Suture deeply, narrowly chan- 

 neled; periphery inflated, well rounded. The base is inflated, well 

 rounded, and marked by the continuations of the axial ribs. The broad 

 umbilicus shows slender spiral threads on the umbilical wall. The last 

 whorl is solute for about one-eighth of a turn. The posterior angle of 

 the solute portion is marked by a conspicuous carina. The aperture is 

 oval ; the peristome is double, the outer very broadly expanded, reflected, 

 and thickened on the outer and basal lip and the anterior half of the 

 columella ; the inner is reflected over and appressed to the outer for about 

 half of the width of the outer lip. 



