HISPANIOLAN AND BAHAMAN ANNULARIIDAE 99 



fifth of a turn. Aperture broadly oval; peristome double, the outer 

 narrow on the parietal and outer lip, wider at the junction of the basal 

 and inner lip, forming a strong auricle at the posterior angle ; the outer 

 peristome is marked by concentric lamellae which are well emphasized 

 at the auricle; inner peristome stout, strongly exserted and slightly re- 

 flected. Operculum typically coloninid. 



The type (U.S.N.M. No. 363827) was collected by Dr. W. L. Abbott 

 in debris from under a rock by a small cave at the small savanna, one 

 hour's walk west of Maniel Viejo, Bahoruco Mountains, Dominican Re- 

 public, at an elevation of 2,500 feet. It has 5 whorls remaining and meas- 

 ures: Height, 17.3 mm.; greater diameter, lo.o mm.; lesser diameter, 

 7.5 mm. 



U.S.N.M. No. 536870 contains 43 topotypes. 



COLONIN.\ MOI-ENSIS, new species 



Plate 15, Figure 1 



Shell elongate-ovate, pale yellowish brown, with a zone of white at 

 the summit; peristome white. Nuclear whorls 1.7, inflated, strongly 

 rounded, forming a depressed mammillated apex. Postnuclear whorls in- 

 flated, strongly rounded, and marked by closely spaced, slender, sub- 

 lamellar axial riblets, of which 152 are present on the last turn. These 

 riblets become fused at their summit into a solid plate. In addition to 

 the axial sculpture, the whorls are marked by strong spiral cords, of 

 which seven are present on the first and second and eight on the last 

 turn. These spiral cords render the axial riblets decidedly nodulose, the 

 nodules being elongated and having their long axis parallel with the axial 

 sculpture. They give the impression of a series of pearls strung on a 

 thread. Suture rendered inconspicuous by the fused riblets at the summit. 

 Periphery inflated, strongly rounded. Base short, inflated, strongly 

 rounded, narrowly openly umbilicated, and marked by the continuation 

 of the axial ribs and seven spiral cords. Within the edge of the umbilicus 

 five additional cords may be seen. There are probably more hidden by the 

 reflected outer peristome. Aperture broadly oval ; peristome double, the 

 outer broadly expanded on the inner lip and denticulated on its outer 

 margin, less expanded on the parietal wall and basal and outer lip, but 

 forming a strong auricle at the posterior angle, which continues back- 

 ward as a denticulated carina; the inner peristome is slightly exserted. 

 Operculum strongly calcified and marked by strong retractively curved 

 ribs which are more or less fused to form a plate. The ribs do not 

 extend to the outer limit of the turn of the basal chondroid plate but 

 terminate about one-quarter of the distance before reaching the outer 

 margin. 



The type (U.S.N.M. No. 504019) was collected by Mr. and Mrs. E. 

 C. Leonard at the base of grass tufts on coral rocks near the seashore, 



