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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 85 



CHONDROTHYRETES DELECTABILIS, new species 



Shell small, elongate-ovate, thin, varying in color from uniform 

 flesh-color to pale yellow with or without an axial dark zone behind 

 the peristome and with or without interrupted spiral bands. Nuclear 

 whorls about 2, strongly rounded, smooth, with at least an indication 

 of dark coloration at the suture of the beginning of the turns. 

 Postnuclear whorls well rounded, marked by slender or fairly regular 

 retractively curved axial riblets and spiral threads, the latter a little 

 stronger than the axial riblets. The junction of these two elements 

 forms slender nodules. Suture well impressed. Periphery strongly 



FiGDEE 92. — Distribution of the subspecies of Chondrothyretes delectabilis: (1) amaiili^ , 

 (2) delectaiilis; (3) palmaris; (4) hellamaria. 



rounded. Base marked by the same sculpture that characterizes the 

 spire. Aperture broadly ovate; peristome double, the inner slightly 

 exserted ; the outer broadly flaringly expanded, somewhat fluted and 

 marked by concentric lamellae with a deep cut on the middle of the 

 inner lip posterior to which the peristome is reflected over the um- 

 bilicus, covering this as a broad flap. 



The species ranges from the mogotes on the north side of the 

 Sierra San Andres eastward to the Mogote de Galalon. It breaks up 

 into local races, four of which we are recognizing as subspecies. 



Distribution of the subspecies of Chondrotliyretes delectabilis is 

 shown in figure 92. 



