264 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



diameter, 5.0 mm.; lesser diameter, 4.0 mm. There are 53 riblets 

 present on the first whorl, 67 on the second, 77 on the third, 120 on 

 the fourth, and 69 on the last three-tenths of a whorl. 



TUDORA (RAMSDENIA) NATENSONI CANETENSIS. new subspecies 



Plate 25, Figure 7 



Natenson collected this race at Canete, west of Taco, west of 

 Baracoa, Oriente Province. 



It differs from the typical race in being much larger, stouter, and 

 in having the axial ribs not as conspicuously scalariform. The type, 

 U.S.N.M. No. 535673, has 4.2 whorls remaining and measures: 

 Length, 8.9 mm.; greater diameter, 5.0 mm.; lesser diameter, 4.3 mm. 

 It has 44 riblets on the first whorl, 76 on the second, 128 on the third, 

 and 129 on the last and the fraction remaining. 



TUDORA (RAMSDENIA) PERSPECTIVA ([Gundlach] Pfeiffer) 



Plate 25, Figures 1, 6 



1859. Cydostoma perspectivum [Gundlach] Pfeiffer, Malakozool. Blatter, vol. 6, 



p. 72. 

 1865. Ctenopoma perspectivum Pfeiffer, Monographia pneumonopomorum 



viventium, suppl. 2, pp. 116-117. 

 1915. Rhytidopoma perspectivum Pilsbry, Nautilus, vol. 28, p. 136. 

 1920. Ramsdenia perspectivum Henderson and Bartsch, Proc. U. S. Nat. Mus., 



vol. 58, p. 79. 



Shell elongate-conic, pale horn colored. Nuclear whorls 2, forming 

 a subglobular apex, the whorls of which are well rounded and micro- 

 scopically granulose, except for the last portion of the last turn, which 

 shows the beginning of the postnuclear sculpture. The first two post- 

 nuclear turns are solute, very openly and broadly coiled, and marked 

 by rather distantly spaced, retractively slanting, axial riblets; the 

 later turns are strongly rounded and marked by slightly retractively 

 curved, axial riblets which are very poorly developed and tend to 

 become obsolete on the last whorl. The stronger of these riblets are 

 developed into conspicuous auricles at the summit. In the specimen 

 described and figured, 108 of these ribs are present on the next to 

 the last whorl and 136 on the last. Suture strongly constricted. 

 Periphery well rounded. There is an indication of a feeble spiral 

 thread immediately below the periphery and two additional strong 

 spiral cords on the base render the axial riblets strongly scalloped at 

 their junction. The umbilicus is broadly open, and the umbilical 

 wall is marked by the feeble continuation of the axial riblets and 3 

 obsolete spiral threads, which also render the axial riblets scalloped. 

 Last whorl solute for about one-half a turn. Aperture subcircular; 

 peristome double, the outer strongly fimbriated, the strongest fim- 



