Descriptions of New Species of Bullia and Marginella, with 

 Notes upon G. B. Sowerby, Jr's. Monograph of the latter 

 genus, hij John H. Redfield. Read May 22J, 1S18. 



1. BULLIA plicata. Plate XVII., Fig. 1. 



Testa elongato-turrila, albido-Iutescente : anfractibus septem planatis, superne 

 crenulato plicatis, inferne callosis ; columella excavata, subsinuata, callosa ; labro 

 tenui ; apertura tevi, castanea, anticn late emarginata. 



Description. — Shell elongate, turreted, yellowish white, tinged 

 on the back with brownish yellow. Whorls seven, flattened, cre- 

 nately plicated beneath the sutures. The upper whorls are cov- 

 ered with a callosity extending from their base over about three 

 fourths of their height, leaving only the sutural plications exposed. 

 This callosity follows the turns of the shell, until it reaches the 

 commencement of the last whorl, where it loses itself upon the 

 columellar lip. Columella excavated, slightly twisted, white. — 

 Three or four prominent striae emerge from beneath the columel- 

 lar callosity in a line with the termination of the suture, and con- 

 tinue to the basal or anterior portion of the right lip. Below these 

 striae is an area covered with fine incremental striae concentric to 

 the basal notch, which is broad, and rather deep. Right lip thin. 

 Aperture smooth, colored with chesnut-brown toward its upper 

 portion. 



Length 3.1 inches (79 millimetres.) Breadth 1.7 inches (43 mil- 

 limetres.) Spiral divergence 30°. 



Habitat. — Not precisely known, but from the fact that it was 

 found in company with Monoceros lugubre Sow. and other shells in- 

 habiting the East Pacific, it i3 probable that it was brought from 

 California or Central America. 



Remarks. — This is the largest species of Bullia yet known, 

 though not so ponderous as B. gradata (Desh.) Reeve. It can- 

 not be confounded with any of the species described in Reeve's 

 Monograph of that genus. 



