258 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



calcareous granules, which thins out toward the edoje, leaving an 

 uncovered zone on the outer fourth. 



The animal of C. {C.) tost a tosta taken on the north side of the 

 Chorrera near Banos San Vicente, was described by Bartsch in 1928, 

 as follows: Animal short, smoky gray, paler around the base of the 

 tentacles and the anterior portion of the snout. Tentacles coral-red, 

 becoming paler toward the base. Foot longitudinally medially cleft. 

 Locomotion alternate on the two sides. 



The animal of C. (C.) tonta lactea also was described by Bartsch, as 

 follows: Animal short, ashy gray; tentacles coral-red, brownish at 

 the tip, flesh-colored at the base. 



That of C. (0.) tosta hesper/'a, Bartsch described as follows: 'Body 

 smoky gray, with the base of the tentacles and the edge of the snout 

 flesh-color. The tentacles pass from flesh-color to pale brown to 

 orange, the latter color constituting the major portion. It suspends 

 itself bj' a mucous thread. 



This species ranges from the Sierra de la Chorrera westward 

 through the Organ Mountains to Pan de Azucar and the Sierra del 

 Infierno. "We must, however, except the Mogote El Queque and the 

 Ensenada Palmaritas, where C. (C.) rutila holds forth. 



Througli this range the species breaks up into a series of subspecies, 

 which the following key will help to differentiate: 



Distribution of the subspecies of C. (C.) tosta is shown in figure 86. 



KEY TO THE SUBSPECIES OF CHONDROTHYRA (CHONDROTHYRA) TOSTA 



Axial dark zone behind peristome present. 

 Ground color white or pale yellow. 



Shell moderately stout tosta 



Shell slender hesperia 



Ground color not white or pale yellow. 



Ground color bright yellow or orange. 



Entire shell yellow or orange aurantia 



Entire shell not yellow or orange. 



Last half whorl only deeply colored pertosta 



Axial dark zone behind peristome absent lactea 



CHONDROTHYRA (CHONDROTHYRA) TOSTA TOSTA, new subspecies 



Plate 15, Figukes 2, 7 



In this race, Avhich inhabits the Ensenada de los Banos San Vi- 

 cente, including the Sierra San Vicente, part of the Chorrera and 

 part of the Sierra Vinales, the ground color is white or faintly 

 yellowish. There is always a dark band even in the white shells 

 immediately behind the peristome, which shines through the sub- 

 stance of the shell and tints the outer lip of the aperture at this 

 place. The shells may also be banded with spiral zones of brown. 



