HISPANIOLAN AND BAHAMAN ANNULARIIDAE 



103 



occur on the first, 84 on the second, 108 on the third, and 140 on the last 

 turn. At irregular intervals two or three of these riblets are gathered 

 into tufts at the summit. The spiral sculpture consists of feeble, low, 

 rounded threads, of which five occur on the first, six on the second, and 

 eight on the remaining turns between the summit and the periphery. 

 The junctions of the axial ribs and spiral threads form very slender 

 elongated nodules, the long axis of which coincides with the axial sculp- 

 ture ; they also render the axial riblets wavy. Suture slightly channeled. 

 Periphery of the last whorl strongly rounded. Base short, well rounded, 

 moderately openly umbilicated, and marked by the continuation of the 

 axial riblets and six spiral threads, the latter increasing in size from the 

 periphery toward the umbilicus. The inside of the umbilical wall is also 

 marked by the axial ribs and 14 feeble spiral threads, which decrease 

 in size from without inward. The umbilicus is to a great extent over- 

 shadowed by the reflected outer peristome. The last whorl is almost ap- 

 pressed to the preceding turn. Aperture broadly oval, almost subcircular ; 

 peristome double, the outer strongly expanded with a conspicuous auricle 

 at the posterior angle, of almost even width on the outer lip, a little 

 more broadly expanded at the posterior angle of the aperture, and least 

 so on the parietal wall ; the inner peristome is very stout, erect, and 

 slightly reflected. Operculum typically haitipomid. 



The type (U.S.N.M. No. 355344) was collected by Dr. W. L. Abbott 

 on Catalina Island, Dominican Republic. It has 4.5 whorls remaining 

 and measures: Height, 11.3 mm.; greater diameter, 5.9 mm.; lesser 

 diameter, 5.3 mm. 



Fifty topotypes (U.S.N.M. No. 355345) yield the following average 

 measurements : 



This subspecies may be easily distinguished from Haitipoma marcense, 

 with which it shares the strongly expanded peristome of the inner 

 lip, by its much more slender shape. 



HAITIPOMA MARCENSE, new species 



Plate 15, Figure 7 



Shell elongate-conic, pale brown with an orange tinge. Nuclear whorls 

 1.5, well rounded, microscopically granulose, forming a rather small 

 apex. Postnuclear whorls somewhat inflated, strongly rounded, marked 

 by retractively slanting, sublamellar axial riblets, of which 88 occur on 

 the first of the remaining turns, 136 on the second, 158 on the third, and 



