246 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



Still another cord. The axial sculpture consists of numerous, fine, very 

 closely spaced, quite regular, slightly retractively slanting, sublamel- 

 lar axial riblets, which render the spiral cords feebly nodulose, the nod- 

 ules being elongate with their long axis coinciding with the axial ribs, 

 of which 228 occur on the last turn. Some of these axial riblets at 

 irregular intervals become fused at the summit to form moderately 

 strong denticles. Suture moderately constricted. Periphery well rounded. 

 Base moderately long, narrowly umbilicated, and marked by eight spiral 

 threads almost as strong as those on the spire and the continuation of 

 the axial riblets. The last whorl is solute for about one-fifth of a turn 

 and slightly decurrent. Aperture oval; peristome double, forming a 

 moderately constricted auricle at the posterior angle, which shows con- 

 centric lines. The outer peristome is broadest on the inner lip, narrow 

 on the parietal wall, and becomes fused with the inner on the outer lip ; 

 the inner peristome is very slightly exserted and reflected. Operculum 

 typically coloninid. 



The type (U.S.N.M. No. 536839) I collected near Albert Town on 

 Fortune Island, Bahamas. It has 4.3 whorls remaining and measures: 

 Length, 18.0 mm.; greater diameter, 10.3 mm.; lesser diameter, 8.9 mm. 



U.S.N.M. No. 391522 contains ^2 topotypes from the same source. 



U.S.N.M. No. 390742 contains 81 specimens collected by Bartsch on 

 the south side of Fortune Island near the upper landing. 



U.S.N.M. No. 391750 contains 23 specimens collected by Bartsch at 

 Walker's Bay. 



U.S.N.M. No. 392360 contains 5 specimens collected by Bartsch on 

 the south side of the lagoon near Albert Town, Fortune Island. 



U.S.N.M. No. 391745 contains 26 specimens collected by Bartsch on 

 the east side of the lagoon. 



U.S.N.M. No. 168325 contains 14 specimens collected by Henderson 

 and Simpson on Fortune Island. 



This species can readily be distinguished from C. nana by its larger 

 size. 



COIiONINA NANA, new species 



Plate 38, Figure 12 



Shell rather small, ovoid. The nuclear whorls are decollated in all our 

 specimens. The postnuclear whorls are strongly rounded and marked by 

 sublamellar spiral cords, of which eight are present on all the whorls 

 between the summit and the periphery. The axial sculpture consists of 

 numerous, slender, sublamellar, closely spaced riblets, which render the 

 axial ribs weakly nodulose at their junction, the nodules being elongate 

 with their long axis coinciding with the axial sculpture. Of these riblets 

 256 occur on the last whorl. The axial riblets render the summit of the 

 whorls minutely denticulated. Suture narrowly deeply channeled. Pe- 



