HISPANIOLAN AND BAHAMAN ANNULARIIDAE 143 



also carries the axial ribs and ii spiral threads. On both base and um- 

 bilical wall, the junction of the axial ribs and spiral threads form nod- 

 ules. Aperture circular; peristome double, the inner well exserted; the 

 outer broadly obliquely expanded, with a deep sinus at the junction of 

 the inner lip and parietal wall. Posterior to this sinus, the outer peristome 

 is rolled inward to almost form a tube. The outer peristome is marked 

 by concentric lines. 



The type (U.S.N.M. No. 356198) was collected by Dr. W. L. Abbott 

 at Laguna, 4 miles north of Samana, Samana Bay, Dominican Republic. 

 It has 4.5 whorls and measures: Height, 5.0 mm.; greater diameter, 

 8.2 mm. lesser diameter, 6.0 mm. 



U.S.N.M. No. 536872 contains 73 topotypes from the same source. 



Genus ABBOTTELLA Henderson and Bartsch 



1920. Abbottella Henderson and Bartsch, Proc. U. S. Nat. Mus., vol. 58, 

 pp. 74-75. 



Shell depressed-helicoid, marked by axial ribs of two series; stronger 

 lamellar elements are separated by finer threads. The spiral sculpture 

 consists of feeble cords, which at their junction with the lamellar axial 

 ribs form decided cusps; these in fact are developed into hollow spines 

 in some of the species. Base with broad, funnel-shaped umbilicus, marked 

 by the continuation of the sculpture characterizing the spire; this also 

 extends upon the umbilical wall. Aperture circular; peristome double, 

 the outer broadly flaringly expanded, the inner exserted. Operculum with 

 central nucleus bearing a decidedly elevated lamella which rises vertically 

 to the outer third where it bends obliquely outward. 



Type species: Chondropoma moreletianum Crosse = Abbottella more- 

 letiana (Crosse). 



KEY TO THE SPECIES OF ABBOTELLA 



Shell depressed-helicoid. 



Spiral threads of uniform strength. 

 Axial ribs of uniform strength. 



Junctions of axial ribs and spiral threads hispid wilhelmi 



Junctions of axial ribs and spiral threads not hispid. . . newcombi 

 Axial ribs not of uniform strength. 



Junctions of axial ribs and spiral threads nodulose haitensis 



Junctions of axial ribs and spiral threads spinulose. . . moreletiana 

 Spiral threads not of uniform strength. 



Outer peristome rolled inward toward the inner peristome 



at basal columellar angle samanensis 



Outer peristome not rolled inward toward the inner 



peristome at basal columellar angle sanchezi 



Shell not depressed-helicoid. 

 Shell helicoid. 



Axial ribs very regularly spaced. 



Lamella of operculum decidedly oblique adolphi 



Lamella of operculum almost vertical sosuaensis 



