dall: mollusca and braciiiopoda. 325 



U. S. S. " Albatross," station 3392, in the Gulf of Panama, in 1270 fathoms, 

 hard bottom, temperature 36°.4 F. U. S. N. Mus. 123,032. 



Tlie descriptiou is written from an adult with base defective, and a young shell 

 of four wliorls. The adult aperture may therefore present some features not noted 

 here. 



This genus occurs in the Middle Eocene of both the Paris basin and Alabama. 

 A recent species, C. migrans Dall, has been described from eiglity fathoms in the 

 Straits of Florida, and probably further rcsoarclies iuto the deep-sea faunas will 

 reveal others. So far no specimen with the soft parts or operculum has been 

 obtained, 



Begmnziidae. 



SEOUENZIA Jeffrkys. 



Seguenzia occidentalis Dall, n. sp. 



Shell small, pearly under an opaque dull wliitc outer coat, with five turbinate 

 wliorls and a small globular, subtranslucent, glossy nucleus; whorls with three prom- 

 inent spiral keels, the sttongest at tlie periphery, tlie others at the shoulder and 

 the edge of the base, about equidistant from the suture and each other ; the base 

 with three smaller more adjacent spirals, and between them and the umbilicus four 

 or five still finer spiral threads; axial sculpture in the interspaces of almost 

 microscopic elevated arcuate radial lines in harmony with the lines of growth and 

 crossed by extremely fine microscopic spiral striae ; base rounded, the umbilicus 

 perforate, partly shadowed by the thin reflected edge of the pillar; aperture sub- 

 quadrate, deeply widely notched near the suture ; the body with a thin wash of 

 callus, the pillar vertical, simple, lightly reflected, at the anterior end forming a 

 right angle with the anterior margin of the aperture ; operculum wanting. Lou. 

 of shell, 2.9; of aperture, 1.7; max. diam. 3.1 mm. 



U. S. S. "Albatross," station 3418, ofT Acapulco, Mexico, in 660 fathoms, sand, 

 bottom temperature 39° F. U. S. N. Mus. 123,033. 



The chief features of tliis species are the perforate umbilicus, the Trochoid 

 form, and the three principal carinae, a combination quite sufficiently distinguish- 

 ing it from any of the hitherto described Atlantic species. 



Seguenzia stephanica Dail, n. sp. 



Shell small, whitish, nacreous, sliining through a translucent outer coating ; 

 with about six whorls and a minute translucent glossy subglobular nucleus ; 

 whorls with four strong spiral keels, the posterior pair somewiiat nearer tlie 

 suture and eaeii other tlian they arc to the anterior pair, tliat is, the peripheral 

 interspace is widest ; the anterior keel of tlie four forms tlie margin of the base 

 of the last whorl, but the suture is wound on the third keel; base with about 

 eight much smaller, adjacent, simple, spiral threads extending to the pillar, the 



