HISPANIOLAN AND BAHAMAN ANNULARIIDAE 249 



Subfamily Annulariinae Henderson and Bartsch 



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

 p. 71. 



Shell ranging in form from depressed helicoid to elongate-conic. The 

 axial sculpture may be almost obsolete or it may consist of strong ribs 

 or many slender lamellae, which may or may not be gathered into tufts 

 at the summit. The spiral sculpture may be absent, confined to the um- 

 bilicus, or cover spire and base. In strength the spiral sculpture varies 

 from fine threads to strong cords. Breathing devices are present in some 

 groups and absent in others. They range from a mere notch or slit punc- 

 ture to a pore v^^ith external siphon. The operculum may be flat or con- 

 vex on the outside, provided with a calcified lamella, which rises from 

 the inner edge of the whorls. This lamella may be vertically placed upon 

 the basal plate or it may be obliquely situated or reflected to parallel the 

 basal plate. It may be almost smooth or ribbed. 



Type genus: Annularia Schumacher. 



COLONELLA, new genus 



Shell small, elongate-conic, when truncated subcylindric, marked by 

 slender axial riblets, which are gathered into tufts at the summit that 

 project as conspicuous denticles above the suture. The spiral sculpture 

 consists of weak threads which may or may not crenulate the axial ribs. 

 Last whorl solute for part of a turn. Base openly umbilicated. Aperture 

 oval; peristome double, the outer moderately expanded forming an 

 auricle at the posterior angle. Operculum with a slender, well raised out- 

 wardly reflected lamella which becomes much thickened on the last turn 

 and slopingly downward curved toward the chondroid basal plate and 

 marked by rather strong, retractively curved riblets. 



Type species : Chondropoma mariguanensis Clench = Colonella ma- 

 riguan ensis ( Clench ) . 



KEY TO THE SPECIES OF COLONELLA 



Last whorl solute. 



Denticles at the summit consisting of fused axial riblets.. mariguanensis 

 Denticles at the summit not consisting of fused axial riblets.. acklinsensis 



Last whorl not solute watlingensis 



COL,ONEL,L,A BIABIGUANENSIS (Clench) 



Shell small, almost subcylindric, varying from unicolor horn-color to 

 purplish chestnut-color. The shells may be unicolor or banded. Nuclear 

 whorls almost 2, smooth except for microscopic granulations, forming 

 a slightly mammillated apex. The postnuclear whorls are marked by 

 slightly retractive, slender axial riblets, which vary somewhat in strength 

 and spacing. At irregular intervals several of these riblets are gathered 

 into hollow tufts at the summit. Suture strongly constricted. Periphery 

 well rounded. Base moderately widely openly umbilicated, marked by 

 the continuation of the axial ribs and several low, rounded, spiral threads 



