CUBAN ANNULAEiroAE TORRE AND' BARTSCH 383 



whorl. These sublamellar riblets are strongly expanded at the sum- 

 mit, the expanded portion being adnata to the precedmg turn as 

 slender auricles. Between these sublamellar riblets quite strong axial 

 threads are present, which vary from 2 to 4 in number. Suture well 

 constricted. Base short, inflated, strongly rounded, broadly, openly 

 umblicated, and marked by the continuation of the axial riblets. The 

 umbilical wall is marked by the closely approximated axial riblets and 

 by 10 feeble spiral threads, which are rather irregularly spaced, and 

 of which the outer is the strongest. Last whorl solute for one-fourth 

 of a turn. Apertiu-e broadly oval; peristome double, the inner and 

 outer coextensive on the outer and basal lip, slightly separated on the 

 inner lip, and more so on the parietal wall; the outer forms a weak 

 auricle at the posterior angle of the aperture. Operculum typically 

 annidarid. 



The type, U.S.N.M. No. 356326, was collected by Mr. Henderson 

 at Farallones de Canapii, near Cayo del Rey, Oriente Province. It 

 has 5.0 whorls and measures: Length, 10.8 mm.; greater diameter, 

 10.3 mm.; lesser diameter, 8.0 mm. 



Subgenus Chondropomatus Henderson and Bartsch 



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

 p. 59. 



Shell of turbinate form, marked by strong axial ribs, betw^een 

 which finer threads parallel to the ribs are present. The axial sculp- 

 ture extends into the open umbilicus, the wall of which is marked by 

 strong spiral cords. Operculum with the merest indication of the 

 beginning of a lamella. 



Type: Annularia (Chondropomatus) lata ([Gundlach] Pfeiffer). 



Henderson and Bartsch created the above subgenus for Cyclostoma 

 latum (Gundlach) Pfeiffer and placed it in the genus Chondropoma of 

 the subfamily Chondropominae. Much additional material now 

 causes a realignment of this group. All the characters of the shell, 

 with the exception of the operculum, are those of the subgenus Annul- 

 arelh, of the genus Annularia, in w^hich genus it is now placed, since 

 it is believed that the reduction of the lamella to the vanishing point 

 or even its absence had best be considered a specialization along the 

 line of reduction, rather than an expression of a phylogenetic rela- 

 tionship. This realignment is also confirmed by the zoogeographic 

 position of the group. 



KEY TO THE SPECIES OF THE SUBGENUS CHONDROPOMATUS 



Peristome white lata 



Peristome yellow raimetica 



