52 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 70 



more or less undulated by the sculpture; axial sculpture of (on the 

 last whorl 10 or 11) well-marked rounded ribs with equal or wider 

 interspaces, crossing the whorls on the spire, obsolete on the base, 

 and very fine silky incremental lines; spiral sculpture of (on the spire 

 two) cords near the periphery and one close to or hidden by the suc- 

 ceeding suture; these become prominent on the periphery of the last 

 whorl and nodulose where they cross the ribs; in front of them the 

 base and canal are sculptured with very fine close spiral threads; 

 aperture moderate, outer lip simple, body with a thin wash of enamel; 

 canal well developed, flexuous; axis minutely pervious. Length of 

 shell, 9.5; of aperture and canal, 4.5; diameter, 5 mm. U. S. Nat. 

 Mus. Cat. No. 108317. 

 Off Georgia, numerous specimens. 



Family CHRYSODOMIDAE 



Genus CHRYSODOMUS Swainson 



Subgenus Siphonorbis Morch 



SIPHONORBIS PERMINUTUS. new species 



Shell small (immature?), stout, white, with a planorboid white nu- 

 cleus of one and a half whorls, and three and a half subsequent well- 

 rounded, rapidly increasing whorls; suture distinct, not deep; axial 

 sculpture of rather obvious fine close incremental lines which mi- 

 nutely crenulate the spiral; spiral sculpture of (on the penultimate 

 whorl half a dozen) fine spiral threads with wider interspaces which 

 on the last whorl grow closer and coarser anteriorly, covering the 

 whole whorl; aperture ovate, outer lip thin, body erased, pillar atten- 

 uated in front, canal slender, narrower anteriorly. Length of shell, 

 9; of aperture and canal, 6.5; diameter, 5 mm. U. S. Nat. Mus. Cat. 

 No. 107996. 



Off Georgia and Fernandina, not rare. 



The nucleus begins smoothly, quickly develops faint spirals, these 

 gradually increase in strength and merge into the spirals of the adult 

 sculpture; the nucleus of S. ebur Morch, type of the subgenus, is very 

 similar. Most of the specimens obtained were immature and it is not 

 certain that that largest specimen, on which the diagnosis is based, is 

 fully adult. 



Family COLUMBELLIDAE 



Genus ASTYRIS H. and A. Adams 



AST Y RIB PURA Verrill 



Astyris pura Verrill, Tratis, Conn. Acad., vol. 5, pt. 2, p. 515, June, 1882. — 

 Bush, Bull. Mus. Comp. Zool., vol. 23, p. 240, pi. 1, fig. 13, 1893. 



Off Fernandina, 14 specimens. Off the eastern coast of the United 

 States from Cape Cod to Florida, in 70 to 484 fathoms; United 

 States Fish Commission. 



