250 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



red-shelled with red peristome and 1ms the spiral threads more nu- 

 merous and closer spaced than the other known subspecies. 



The specimen figured, U.S.N.M. no. 468729, is one of Arango's 

 cotypes. It has 5.5 whorls remaining and measures : Length, 23.8 mm ; 

 greater diameter, 13.5 mm ; lesser diameter, 9.2 mm. 



TURRITHYRA (TURRITHYRA) HAMLINI (Arango) 



Shell elongate-turreted of pale buff ground color, marked by in- 

 terrupted spiral bands of brown, which may also join to form axial 

 varicial streaks; peristome yellowish white. Nuclear whorls a little 

 more than 2, large, strongly inflated and rounded, smooth, except 

 for a few incremental lines on the last part of the last turn. Post- 

 nuclear whorls also somewhat inflated and strongly rounded, marked 

 on the early whorls by very slender, almost lamellar, rather closely 

 spaced riblets, which on the last whorls are less elevated and more 

 threadlike. These riblets extend over the inflated and strongly 

 rounded periphery and base of the last whorl into the umbilicus. In 

 addition to this, the whorls bear slender spiral threads, which at their 

 junction with the axial riblets form conspicuous cusps on the early 

 turns and rounded nodules on the later whorls, while the spaces 

 enclosed between them are more or less squarish areolations. In the 

 umbilicus the spiral threads are stronger than on the spire. Aperture 

 subcircular, peristome double, the outer moderately broadly ex- 

 panded and reflected, somewhat radially fluted and marked with in- 

 cremental lines, the inner less expanded but also reflected and adnate 

 to the outer. Operculum thin, corneous, covered with a minutely 

 granulose calcareous deposit. Breathing pore on the parietal wall near 

 the posterior angle of the aperture. 



This species, as far as known, is restricted to the mogotes ranging 

 about Kilometer 14, between Pinar del Rio and Luis Lazo. 



KEY TO THE SUBSPECIES OF TURITHYRA (TURITHYRA) HAMLINI 



Cusps formed by junction of axial and spiral sculpture strong on 



later whorls xilaensis 



Cusps formed by junction of axial and spiral sculpture not strong 

 on later whorls. 



Dots of spiral bands usually forming axial bands cerroensis 



Dots of spiral bands usually not forming axial bands hamlini 



TURRITHYRA (TURRITHYRA) HAMLINI XILAENSIS, new subspecies 



Plate 13, Figure 7 



This subspecies comes from Mogote de la Vega de Xila Couret 

 near Mogote del Cerra. It differs from the other two in having 

 the cusps formed by the junction of the axial and spiral sculpture 

 much stronger on the later whorls ; also in being paler and in having 



