320 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



whorls about 2, small, strongly rounded, smooth, with a dark spot 

 at the beginning. Postnuclear whorls inflated, strongly rounded, 

 and marked with very slender sublamellar axial ribs, which are 

 closely crowded but only about one-half or less as wide as the spaces 

 that separate them. The spiral sculpture consists of slender threads, 

 which are less strong than the axial riblets and which render these 

 somewhat wavy, scarcely denticulate. Suture strongly constricted. 

 Periphery inflated, strongly rounded. Base short, inflated, strongly 

 rounded, and marked like the spire. Aperture broadly oval; peri- 

 stome double, the inner little exserted, reflected upon and adnate 

 to the outer which is broadly expanded, somewhat fluted and marked 

 with feeble concentric lamellae, cut in the middle of the inner lip, 

 with the posterior portion of this covering the umbilicus; parietal 

 wall covered with a heavy callus. Breathing pore on the parietal 

 wall near the posterior angle at some distance from the edge, com- 

 municating with the umbilicus and the exterior through the hollow 

 axis and the decollated apex. Operculum paucispiral, covered with 

 a moderately strong calcareous deposit. 



This species ranges through the mountains a little east and west 

 and north of Candelaria. 



"We recognize two subspecies, which the following key will help 

 to distinguish: 



KEY TO THE SUBSPECIES OF CHONDROTHYRELLA (CHONDROTHYRELLA) 



CUZCOENSIS 



Whorls decidely inflated caroli 



Whorls not decidedly inflated , cuzcoensis 



CHONDROTHYRELLA (CHONDROTHYRELLA) CUZCOENSIS CAROLL new subspecies 



Plate 24, Figure 5 



This race, wliich is rather thin-shelled, usually pale horn-color, 

 and interruptedly spirally lined, is decidedly inflated and has very 

 many very slender axial riblets. It comes from the region of Soroa. 



The type, U.S.N.M. no. 367888, was collected by Carlos de la Torre, 

 Jr., at the Finca Sostenido. It has 3.8 whorls and measures : Length, 

 15.0 mm ; greater diameter, 10.8 mm ; lesser diameter, 8.3 nmi. 



Its decidedly inflated whorls easily distinguish it from C. {C.) 

 cuzcoensis cuzcoensis. 



CHONDROTHYRELLA (CHONDROTHYRELLA) CUZCOENSIS CUZCOENSIS, new 



subspecies 



Plate 24, Figure 6 



In this subspecies the shell is much less inflated and the axial 

 riblets a little less slender and less closely spaced than in G. (0.) cuz- 

 coensis caroli. Its distribution is more extensive. We have collected 



