330 REPORT ON ALBATROSS MOLLUSC A DALL. 



deep groove on the anterior side which is widest internally, since the 

 lips of the groove fold over one another in most eases, so that the proc- 

 esses contain a permanent subtubular gutter. In .1/. centrifugus the 

 varical spines are triangular in section, the anterior margins do not ap- 

 proach one another, and a shallow median sulcus on the front of the 

 spine is the only representative of the groove of M. Leeanus. Below 

 the main spine on each varix in M. centrifugus are three smaller flat 

 spines ; on M. Leeanus the varix is rounded and without spines. The 

 intervarical node in M. Leeanus is obsolete or obscure and rounded ; in 

 M. centrifugus it is much more prominent in proportion and forms an 

 oblique rather narrow rib with a kind of elbow at the periphery. The 

 most prominent character of M. Leeanus is the rounded, root-like, sleek 

 varical spine. 



It is named in honor of Prof. Leslie A. Lee, of Bowdoin College, in 

 charge of the scientific work of the Albatross party during the voyage. 



The specimeu was a female. The foot is auriculate and double edged 

 in front, short, rounded behind, with nearly smooth sides. The eyes 

 are small, the basal two-thirds of the tentacles behind the eyes is stout 

 and thick, the distal part beyond the eyes much more slender. 



The dentition is typically muricoid, the radula small and narrow, the 

 central 'tooth very wide, very short, and with three inconspicuous den- 

 ticles on its cusp. The soft parts hardly differ externally from those of 

 Murex brandaris L. 



Subgenus PTERONOTUS Swainson. 



Pteronotus phaneus Dall. 



Plate xi, Fig. 1. 



Pteronotus phaneus Dall, Bull. Mus. Coin]) Zool., xviii, p. 201, June, 1889. 



Shell ashy white, elongated, thin, six-whorled. Nucleus translucent, 

 smooth, polished, of about one and a half whorls; whorls slightly eon- 

 vex, appressed to the suture behind them, connected by three continu- 

 ous tin-like varices which in descending the spire make about half a 

 revolution around it; these varices on the upper whorls were extended 

 backward into a little wing-like point with dentate edges; on the last 

 whorl the lines of growth indicate that the thin margin was rounded 

 parallel with the whorl. Transverse sculpture of fine growth lines, and 

 on the last two whorls at the periphery three short little narrow 

 pinched up riblets between the varices; spiral sculpture of fine rather 

 faint stria* and wider undulations, hardly visible except on the varices; 

 of these there are nine or ten on the last varix. Aperture elongate- 

 oval, internally white, thickened, smooth; canal rather long, open, 

 bent back. Maximum longitude of shell, 17; of last whorl, 1.3.5; of 

 aperture, 5; maximum latitude of aperture, 3; of shell, 8 mm . 



Hab. — TJ. S. Fish Commission Station 2662, off St. Augustine, Flor- 

 ida, in 43 1 fathoms, sand j temperature 43°.7 F. ; also at Station 2668, in 

 294 fathoms. 



