144 PROCEEDINGS OF THE NATIONAL. MUSEUM Vol.89 



hollow axial ribs, of which 48 occur on the first, 64 on the second, and 

 78 on the last of the remaining turns m the cotype described and 

 figured. Most of these axial riblets become expanded into broad 

 auricles at the summit, although occasionally they do not. The 

 spiral sculpture consists of slender threads, of which 7 are present on 

 all the whorls. The spiral threads at their junction with the axial ribs 

 render the latter decidedly wavy and frequently hispid. Suture 

 strongly constricted. The sutural space is crossed by the auricles of 

 the expanded ribs, which become attached to the preceding turn. 

 Base short, broadly rounded, widely umbilicated, marked by the con- 

 tinuation of the axial ribs and by about 7 spiral threads. These 

 threads are much stronger at the outer edge of the umbilicus than they 

 are within the umbilicus or posterior to it. At the umbilical angle 

 they render the axial riblets decidedly scalloped. Last whorl solute 

 for about one-third of a turn. Aperture broadly oval; peristome 

 double, the outer moderately broadly expanded and strongly digitate; 

 9 digitations about as wide as the spaces that separate them are present 

 on the outer and basal lip; on the inner lip 4 weaker digitations are 

 present, while on the parietal wall they are absent. These digitations 

 show concentric laminae; inner peristome slightly exserted. Oper- 

 culum typically torrellid. The breathing siphon begins immediately 

 behind the peristome at the posterior angle of the aperture and it is 

 reflected as a slender, twisted, corrugated tube into the umbOicus, 

 which it completely plugs. 



A cotype received from Dr. de la Torre, U.S.N.M. No. 355529, 

 comes from El Mogote, near Ceiba Mocha, Matanzas Province. It 

 has 3.5 whorls remaining and measures: Length, 8.0 mm.; greater 

 diameter, 4.8 mm.; lesser diameter, 3.9 mm. 



This species can easily be distinguished from the others by the 

 extremely strong digitations of the outer peristome. 



TORRELLA (TOHRELLA) DEFICIENS ([Gundlach] Pfeiffer) 



Plate 10, Figure 4 



1857. Cyclostoma deficiens [Gundlach] Pfeiffer, Malakozool. Blatter, vol. 4, 



p. 42. 



1858. Ctenoj)oma deficiens Pfeiffer, Monographia pneumonopomorum viven- 



tium, suppl. 1, p. 104. 

 1920. Torrella {Torrella) deficiens Henderson and Bartsch, Proc. U. S. Nat. 

 Mus., vol. 58, p. 69. 



Shell elongate-conic, flesh colored. Nuclear whorls 2, strongly 

 inflated, well rounded, microscopically granulose, forming a mammil- 

 latcd apex. Postnuclear whorls inflated, strongly rounded, marked 

 by almost vertical, slender, hollow, retractively curved axial ribs, of 

 which 61 occur upon the first of the remaining turns in the cotype 



