CUBAN ANNULiARiroAE — TORRE AND BARTSCH 281 



spiral threads, which are a little broader and stronger than those on 

 the rest of the base. Aperture broadly oval; peristome double, the 

 inner but slightly exserted and appressed to the outer, but distinct 

 all around; the outer narrowly expanded and slightly reflected, 

 forming a conspicuous auricle at the posterior angle, wliich is adnate 

 to the preceding turn. Operculum with the nucleus halfway between 

 subcentral and submarginal, bearmg a strong calcareous lamella, 

 which is reflected to parallel the chondroid plate; the various tm-ns of 

 the calcareous lamella touch each other so as to form a continuous 

 plate; the calcareous lamellae are marked by strong, retractively 

 curved tlu'eads. 



The specimen described and figured, U.S.N.M. No. 356362, is one 

 of 5 topotypes from the Poey collection. It has 4.5 whorls remaining 

 and measures: Length, 23.9 mm.; greater diameter, 15.8 mm.; lesser 

 diameter, 12.7 mm. 



Tills species is confined to the region of the Taco Taco River and 

 Rangel, Pinar del Rio Province. 



Genus ANNULARIA Schumacher 



1S17. Annularia Schumacher, Essai d'un nouveau systeme des habitations des 

 vers testaces, pp. 60, 196. 



Shell ranging in form from depressed-helicoid to turbinate to 

 elongate-conic. The sculpture may be almost obsolete or it may 

 consist of axial riblets only, or of axial riblets and spiral threads; the 

 latter may be confined to the umbilicus, or it may be present on the 

 entire shell. There is a great range of variation in the strength of 

 these sculptural features in different species. Breatliing devices may 

 be present or absent. The operculum consists of a chondroid plate, 

 composed of a number of whorls, which bear a calcified spiral lamella 

 on their inner edge; the lamella is obliquely deflected outward. The 

 lamella on the succeeding turns does not fuse with that of its prede- 

 cessor; there is always a space separating it from its neighbor. This 

 lamella is always finely, obliquely striated, the striations varying 

 considerably in strength in different species. 



Type: Turbo lincina Linnaeus. 



Typical Annularia has not been found in Cuba. 



KEY TO THE CUBAN SUBGENERA OF THE GENUS ANNULARIA 



Breathing siphon present. 



Umbilicus open Annularodes 



Umbilicus closed Annularodisca 



Breathing siphon absent. 

 Breathing pore present. 



Axial ribs articulated Annularops 



Axial ribs not articulated. 



Axial sculpture predominant Annularodella 



Spiral sculpture predominant Eutudora 



