AKT. 18 SMALL SHELLS DREDGED BY "aLBATEOSS " DALL 125 



c&,riiiae are all developed the thin margin is modified and the aper- 

 ture is angulated by them; in some specimens faint spiral striation 

 is indicated on the surface between the carinae; the margin of the 

 aperture in the adult is continuous over the body of the shell. Max- 

 imum diameter, 3.5 mm.; minimum diameter, 2.9 mm.; height, 

 1.3 mm. U. S. Nat. Mus. Cat. No. 108396. 



Numerous off Georgia. 



The periostracum on Episcynia is extremely fugacious, and it is not 

 prudent to assume that these and other small shells dredged and show- 

 ing none are normally without one. A few have a persistent perios- 

 tracum, and there is no good reason to suppose that others never pos- 

 sess one. This interesting species is named in honor of the late J. B. 

 Henderson, jr. 



Genus VITRINELLA C. B. Adams, 1850 



VITRINELLA MASSARITA, new species 



Shell small, smooth, white, trochiform with three and one-half 

 whorls, the nucleus globular; suture deep, the inflated whorls giving 

 a somewhat turrited appearance to the shell; base amply rounded, 

 the umbilicus minutely perforate, the whorl evenly rounded into it; 

 aperture circular, the margins thin, sharp, united over the body; the 

 only sculpture very faint incremental lines. Height, 1.5 mm.; diam- 

 eter, 1.7 mm. U. S. Nat. Mus. Cat. No. 108137. 



Three specimens, off Fernandina. 



VITRINELLA CERION, new species 



Shell small, white, smooth, polished, with about four whorls includ- 

 ing a minute globular nucleus; whorls well rounded, separated by a 

 distinct not deep suture in front of which is a narrow, flattish area; 

 sculpture only of a few faint spirals on the earlier part of the spire; 

 base well rounded with a small perforate umbilicus; aperture nearly 

 circular, the margins united over the body by a thin layer of enamel. 

 Height, 1.5; diameter, 1.8 mm. U. S. Nat. Mus. Cat. No. 108433. 



One specimen, off Georgia. 



The general form recalls that of Helix chersina Say. 



VITRINELLA RHYSSA, new species 



Shell small, depressed, white, with about two and one-half rapidly 

 enlarging whorls following a small glassy globular nucleus; suture 

 distinct, not deep ; sculpture of close even prominent incremental lines 

 over the whole shell; base rounded, umbilical pit excavated; aperture 

 oblique, the margins separated by the body, slightly angular at their 

 junction; from the lower angle a thread decends into the umbilicus. 

 Height, 1.3 mm.; diameter, 2.1 mm. U. S. Nat. Mus. Cat. No. 

 1081276. 



One specimen, off Ferandina. 



