FAMILY PURPURIDZ — FUSUS. 143 
GENUS FUSUS. Lamarck. 
Animal incompletely known, but not differing essentially from that of the Pyrula. Marine. 
Shell, stout, elongated, fusiform, tapering to both ends, without varices : spire elevated ; 
aperture oval, ending in a straight or slightly curved canal; columella smooth ; lip acute, 
without a notch. Opercle horny, with the nucleus at the smaller end. 
Fusus SCALARIFORMIS. 
PLATE VII. FIG. 182. 
(STATE COLLECTION.) 
F. scalariformis? Goun, Invertebrata of Mass. p. 288, fig. 203. 
Description. Shell fusiform, elongate, tapering. Whorls six or seven, moderately rounded : 
suture very distinct. ‘The whole upper surface covered with fifteen prominent equidistant 
and vertical ribs, which become obsolete on the three upper whorls; the intervening spaces 
smooth. Lip arched, simple, not crenated. Aperture not quite half of the total length, oblong- 
oval, and ending in a narrow recurved canal beneath: columella concave. 
Color, brownish; white within. 
Length, 1.8; of aperture and canal, 0°8. 
This shell I had named I". borealis many years since, believing it then to be an undescribed 
shell. It was sent to me from the northern coast. Since the appearance of Dr. Gould’s 
Report on the Shells of Massachusetts, I find that it bears a very close resemblance to the 
scalariformis of that author. The following are the chief differences: In my specimen, the 
ribs are smooth and solid, without any apperance of being composed of imbricated scales ; 
there is no appearance of revolving lines in the intervening spaces; the beak is not wrinkled, 
to any apparent degree, by the transverse terminations of the ribs. It is proper, however, to 
add, that my specimen is old, and apparently weathered. I have received since from the 
Rev. Mr. Linsley, a specimen 1°2 in length, with the ribs not imbricated, taken in Long- 
island sound. It is placed, however, under the above name provisionally, until I can have 
better opportunities for comparison and description. 
