282 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



CHONDROTHYRETES DELECTABILIS AMABILIS, new subspecies 



Plate 17, Figure 4 



This race conies from the Mogote de Galalon, east of La Pahna. 



The type, U.S.N.M. no. 468805, is a complete specimen having 7.0 

 ■whorls and measures: Length, 18.7 mm; greater diameter, ll.G mm; 

 lesser diameter, 7.9 mm. 



It has the dark axial zone behind the peristome and four inter- 

 rupted spiral bands between the summit and suture, but here the 

 rays on the outside of the outer lip are very feeble. 



CHONDROTHYRETES TENEBRATA, new species 



Shell moderately large, ovate, rather stout, varying in ground 

 color from flesh-color and pale yellow to orange to dark brown. The 

 early whorls usually are darker than the later, somewhat unicolor. but 

 usually banded. The peristome varies from white to orange and may 

 or may not be stiongly rayed. Nuclear whorls almost 2, the first pale, 

 the next very dark, somewhat inflated and strongly rounded. Post- 

 nuclear whorls inflated ; the early ones slightly angulated in the 

 middle and the later ones well rounded and marked by slender, re- 

 tractivel}^ curved, axial and spiral threads, the latter of a little wider 

 spacing than the axial. The junction of these two elements on 

 the early whorls forms feeble nodules ; on the later turns they scarcely 

 merit that designation. Suture well constricted. The axial riblet 

 extends strongly to the suture and gives to this the merest indica- 

 tion of denticulations. Periphery inflated, well rounded. Base 

 sort, inflated, strongly rounded, and like the spire tending toward 

 a little stronger nodulation at the junction of the axial and spiral 

 elements. Aperture broadly oval. Peristome double, the inner 

 slightly exserted and slightly reflected; the outer broadly flaringly 

 expanded, somewhat fluted and marked by concentric lamellae, cut 

 in the middle of the inner lip, the posterior part to the cut is reflected 

 over the umbilicus which it covers. Operculum thin, corneous, cov- 

 ered with a heavy granular calcareous deposit, which has a somewhat 

 fluted appearance. 



The animal of C . tenebrata dlholabris is smoky gray, a little jDaler 

 on the foot and the edge of the snout; darkest on the forehead. Ten- 

 tacles encircled with a flesh-colored ring at their base; the rest scar- 

 let, with the lateral portion of the expanded tip sooty. The in- 

 ternal anatoni}^ shines through behind the tentacles as a pinkish 

 flush. Foot medially cleft; locomotion alternate. 



This species ranges through the Sierra San Andres, some of the 

 mogotes to the south of this and eastward to Guacamayas and the 

 mogotes north and south of this. 



