256 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



whorl. On this and the whorl preceding, the pits between the axial 

 and spiral sculpture give the shell a somewhat reticulated pattern. 

 Suture moderately constricted, rendered slightly serrulate by the 

 riblets on the sunnnit of the turns, which form here a slender pale 

 zone. Aperture broadly oval ; peristome double, the outer decidedly 

 flaringly expanded, slightly channeled at the posterior angle and 

 marked by radial flutings and slender concentric laminae. The 

 inner is but slightly expanded and reflected and adnate to the outer. 

 Operculum thin, with the excentric nucleus covered by a calcareous 

 granular deposit, which is arranged in a somewhat corrugated pat- 

 tern, in which the corrugations have a retractive slant. 



This species comes from Hato Caimito west of Pan de Guajaibon. 



The specimens figured are U.S.N.M. no. 468692. The dark per- 

 fect individual figured has 7.1 whorls and measures: Length, 27.7 

 mm; greater diameter, 16.5 mm; lesser diameter, 11.5 mm. 



Of this species Gundlach {Joe. elf., p. 134) says that the animal is 

 pale rose-red, with the edge of the foot paler and the tentacles 

 uniformly red. 



CHONDROTHYRA (CHONDROTHYRA) SUBEGREGIA, new species 



Shell elongate-ovate, orange or pale brown, with the peristome pale 

 yellow, unicolor or marked with axial streaks of brown, which some- 

 times form slight fulgurations. Peristome wax yellow, conspic- 

 uously rayed with brown on the outer surface and sometimes on the 

 inner. The early whorls are decollated in all our specimens. The 

 postnuclear whorls are marked by slender spiral threads, which are 

 less than half the width of the spaces that separate them, and re- 

 tractively slanting axial tlireads of about the same strength, which on 

 the last whorl, however, l^ecome quite evanescent. Suture well con- 

 stricted, with the merest indication of denticulationg at the summit of 

 the whorls. Periphery and base inflated, well rounded, the latter 

 umbilicated and marked like the spire. Aperture broadly oval; 

 peristome double, the outer very broadly expanded, thin, decidedly 

 lamellose and somewhat radially fluted, tending to the formation of 

 a channel at the broadly expanded portion, which is reflected to 

 partly close the umbilicus. Operculum thin with excentric nucleus 

 covered by a heavy deposit of calcareous granules on the inner three- 

 fourths, which is laid down in a more or less corrugated pattern. 



There are two races of this species known : One from the Mogote 

 de la Jagua and the other from the Sierra San Andres. 



KEY TO THE SUBSPECIES OF CHONDROTHYRA. (CHONDROTHYRA) SUBEGREGIA 



Surface shining; peristome radiatingly rayed subegreg'ia 



Surface dull; peristome not radiatingly rayed paterna 



