370 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



and the last 43 of the strong ribs. The strong ribs terminate in fairly 

 strong cusps at the summit, while the intercalated ribs form feeble 

 nodules. Sutm'c fairly strongly channeled. Periphery of the last 

 whorl well rounded. Base short, well rounded, marked by the 

 continuation of the axial ribs and by 4 slender spiral threads near the 

 umbihcus, which are weaker than the heavier thread marking the 

 outer Umit of the umbilicus. The umbilicus is open and its wall is 

 marked by 1 1 rather strong spiral cords, which render the axial riblets 

 nodulose. The last whorl is adnate. Aperture pear-shaped, nar- 

 rowest at the posterior angle. Peristome double, the outer and inner 

 expanded all around and adnate to each other, separated only at the 

 posterior angle, where the inner forms a sharp shelf above which the 

 outer projects as a hood. Operculum typically annularid, but with 

 the lamella flattened to parallel the chondroid plate on the last whorl. 

 It has, however, the separating channel between the whorls that is 

 characteristic of the group. 



The type, U.S.N. M. No. 535654, was collected by Victor Rodriguez 

 at Zona de Caleta, Maisi, Oriente Province. It has 4.9 whorls and 

 measures: Length, 11.8 mm.; greater diameter, 13.3 mm.; lesser 

 diameter, 9.8 mm. We take pleasiu-e in naming this species for Dr. 

 Rodriguez. 



ANNULARIA (ANNULARELLA) YATERASENSIS (Pfeiffer) 



Plate 50, Figures 4-6 



1865. Choanopotna yaterasense Pfeiffer, Monographia pneumonopomorum 



viventium, suppl. 2, pp. 107-108. 

 1867. Cyclosloma yaterasense Arango, Repert fisico natural Isla de Cubana, 



vol. 2, p. 77. 

 1920. Tudora (Tudorellata) yateracensis Henderson and Bartsch, Proc. U. S. 



Nat. Mus., vol. 58, p. 75. 



Shell depressed-heUcoid, almost helicoid, flesh colored; the interior 

 of the apertm'e with a yellowish tinge. Nuclear whorls 2, well rounded, 

 smooth, except for the last portion of the last turn, which shows the 

 beginning of the postnuclear sculpture. Postnuclear whorls inflated, 

 strongly rounded, marked by strong sublamollar, retractively slanting 

 axial ribs, between which finer threads are present. The stronger 

 ribs are expanded into slight auricles at the summit. Of the stronger 

 of these ribs 48 occm* upon the second, and 42 upon the last. Of the 

 finer threads 2 to 5 occur between the stronger. In addition to the 

 axial riblets, the whorls show mere indications of spiral threads, 

 which render the axial riblets slightly wavy but which do not form 

 cusps or tubercles. Sutiu-e strongly channeled. Periphery well 

 rounded. Base short, well rounded, openly umbilicated, marked by 

 the continuation of the axial ribs. On the umbilical wall 7 spiral 

 threads are present; these are very feeble except for the outermost 

 one, which is quite cordlike. Aperture subcircular; peristome double, 



