CUBAN ANNUUAEIIDAE — TORRE ANB BARTSGH 227 



broadly expanded, the inner slightly exserted; the outer slightly 

 fluted on the outer edge. Operculum tj^pically xenopomid. 



The type, U.S.N.M. No. 493388, was collected by Mr. Henderson 

 at Farallon de Canapii, Cayo del Rey, Oriente Province. It has 7.5 

 whorls remaining and measures: Length, 11.5 mm.; greater diameter, 

 6.3 mm.; lesser diameter, 5.5 mm. 



Tliis species is readily distinguished from X. hystrix by its large 

 number of spiral threads and by its larger number of spines, and from 

 X. hendersoni by lacking the fine spines on the umbilical wall. 



Genus PARACHONDRIA Dall 



1905. Parachondria Dall, Proc. Malac. Soc. London, vol. 6, p. 209. 



Shell ranging in shape from elongate-ovate to elongate-conic, 

 marked by axial ribs only, or by axial ribs and spiral threads, which 

 are confined to the umbilicus, or by axial and spiral threads on spire 

 and base, or slender axial lamellae and subobsolete spiral threads, 

 which give to the axial sculpture an articulate appearance. No 

 breathing device is present. The operculum has the inner portion of 

 its turns covered by a calcareous deposit, which consists of numerous 

 low, retractively curved, fused riblets, which are not fused into a 

 raised lamella at their outer edge, nor does the calcareous deposit 

 extend to the edge of the chondroid basal plate. There is thus left a 

 narrow channel, in the bottom of which the chondroid plate may be 

 seen at the outer edge of each whorl. 



Type: Parachondria fascia Wood. 



The genus is represented by the subgenera Parachondria and Para- 

 chondrops. In the Cuban species the Parachondria characters of the 

 operculum are very poorly developed; they are not nearly as strong as 

 those in the Jamaican species. 



KEY TO THE CUBAN SUBGENERA OF PARACHONDRIA 



Axial and spiral sculpture strong Parachondria 



Axial and spiral sculpture not strong. 



Axial ribs narrow, rendered articulate by the spiral sculp- 

 ture Parachondrops 



Subgenus Parachondria Dall 



1905. Parachondria Dall, Proc. Malac. Soc. London, vol. 6, p. 209. 



Shell elongate-conic, marked by strong axial and spiral threads on 

 spire and base. Opercidum typical parachondroid. 

 Type: Parachondria (Parachondria) fascia (Wood). 



KEY TO THE SPECIES OF THE SUBGENUS PARACHONDRIA 



Last whorl adnate texta 



Last whorl solute abnata 



223580—40 7 



