CUBAN ANNULARiroAE — TORRE AND BARTSCH 263 



broadly, flaringly expanded, more so on the outer lip than on the 

 mner, reflected into a sinus at the posterior angle, and marked by 

 concentric laminae. Operculum typically ramsdenid. 



The type, U.S.N.M. No. 356488, was collected by Mr. Henderson 

 at Camayen, Santa Lucia, Oriente Province. It has a little over 3 

 whorls and measures: Length, 6.2 mm.; greater diameter, 4.3 mm.; 

 lesser diameter, 3.3 mm. 



TUDORA (RAMSDENIA) NATENSONI. new species 



Shell small, elongate-conic, thin, semitranslucent, flesh colored, 

 with the scallops white. Nuclear whorls 2, strongly rounded, forming 

 a globular apex. The first L5 turns of the postnuclear whorls are 

 solute; the rest of the postnuclear whorls are somewhat inflated, well 

 rounded, and marked by sublamellar axial riblets, which appear more 

 or less in series, that is, several stronger riblets will be succeeded by 

 several weaker ones, givmg the shell a somewhat scalariform aspect. 

 These axial riblets are conspicuously expanded into auricles at the 

 summit. There are also several rows of scallops on the axial riblets 

 of the spire, which are arranged in spiral series. These scallops may 

 be hollow. The peripheral series not mfrequently interlocks with 

 those at the summit of the succeeding whorls. Suture strongly 

 constricted. Periphery rendered slightly angulated by the scallops 

 referred to. Base well rounded, marked by three rows of scallops. 

 The last whorl is solute for a fraction of a turn; it is openly umbilicated 

 and marked by the continuation of the axial ribs and spiral cords. 

 Aperture circular; peristome double, the inner slightly exserted; the 

 outer rather broadly expanded all around and conspicuously scalloped 

 at the edge, forming a conspicuous auricle at the posterior angle, 

 which is channeled and backward reflected, marked by a series of 

 concentric lamellae. Operculum typically ramsdenid. 



This species comes from the north coast of Oriente Province. 



KEY TO THE SUBSPECIES OF TUDORA (RAMSDENIA) NATENSONI 



Shell slender natensoni 



Shell stout canetensis 



TUDORA (RAMSDENIA) NATENSONI NATENSONI. new subspecies 



Plate 25, Figure 9 



Natenson collected the typical subspecies at Finca El Retiro (de 

 Silva), and San Alejo, Boca de Taco, Nibuj6n, west of Baracoa, 

 Oriente Province. If differs from T. (R.) natensoni canetensis in 

 being much more slender, and in having the axial ribs much more 

 scalariform. 



The type, U.S.N.M. No. 535670, comes from Finca El Retno. It 

 has 4.3 whorls remaining and measures: Length, 8.3 mm.; greater 



