242 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



equal or heavier spiral threads, which are also of fairly regular spac- 

 ing. The junctions of the axial and spiral threads form small 

 rounded tubercles, some of which near the upper parts of the turns 

 tend toward cusps. This sculpture also characterizes the inflated and 

 well-rounded base, being even stronger here than on the spire. The 

 base is openly umbilicated, the umbilical wall being sculptured like 

 the adjacent area. Aperture large, very broadly ovate, with a slight 

 angulation at the posterior angle. Peristome double, the outer broadly 

 flaringly expanded, radially fluted and marked with concentric in- 

 cremental lines, cut in the middle of the columellar side and having 

 the posterior half reflected to partially cover the umbilicus; there is 

 usually also a flexure in that of the outer lip a little anterior to the 

 posterior angle, giving this part a somewhat channeled effect. The 

 inner peristome is of much lesser extent; it is also reflected and adnate 

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

 deposit. 



The races of this species cluster about the road leading through 

 the Puerta de la Ancon. 



Distribution of the subspecies of T. (T.) sinuosa is shown in figure 

 83. 



KEY TO THE SUBSPECIES OF TURRITHYRA (TURRITHYRETES) SINUOSA 



Shell of red or reddish ground color vicina 



Shell not of red or reddish ground color. 

 Shell of pale buff or white ground color. 

 Interrupted spiral bands conspicuous. 



Axial and spiral threads numerous and crowded hutia 



Axial and spiral threads less numerous and less 

 crowded. 



Greater diameter more than 13 mm sinuosa 



Greater diameter less than 12 mm opposita 



Interrupted spiral bands inconspicuous or absent rhachitica 



TURRITHYRA (TURRITHYRETES) SINUOSA VICINA, new subspecies 



Plate 14, Figure 13 



This race comes from the Sierra San Vicente and the Sierra Vinales 

 where it joins the Sierra Vicente, It is particularly abundant on the 

 walls of the Ensenada Delicia. It is a large subspecies of almost 

 always red or reddish ground color with conspicuous slender inter- 

 rupted spiral bands of brown. Peristome white, sometimes buff or 

 even pale orange. 



The type, U.S.N.M. no. 492724, comes from the Sierra Vinales; it 

 has 5.5 whorls remaining and measures: Length, 26.0 mm; greater 

 diameter, 15.8 mm; lesser diameter, 10.8 mm. 



The red or reddish color is quite characteristic of this subspecies. 



