GASTEROPODA. 369 
oblique cone, having the apex at the posterior fourth of the shell, so 
that the anterior slope is moderate, while the posterior slope is nearly 
vertical. The apex is prominent, acute; reaching forwards like a 
curved beak. ‘The colour is dirty cinereous. The surface is radiated 
by sharp, prominent, compressed ribs, which are alternately larger 
and smaller, to the number of about forty ; and these are crossed: by 
very fine and crowded concentric lines, by which they are delicately 
muricated. Fissure narrow, and narrowing upwards. The interior 
is porcelain-white; the edge is beautifully crenulated by regular fur- 
rows, alternately longer and shorter, deeper and shallower, answering 
to the external ribs. The fissure is rounded, and the vault enclosing 
it is thin, simple, semicircular, and without callus at the summit. 
Length five-eighths of an inch; breadth seven-sixteenths of an inch ; 
height three-eighths of an inch. 
Brought up on the anchor, Puget Sound, Oregon. 
A very curious and large species, and its inequilateral form gives it 
a resemblance to Hipponix. It is much less elevated in proportion to 
its base than any other known species. ‘The ribs are very regular, 
and sometimes still finer radiating lines are found in the interstices. 
Figures 475, 475 a, 475d, dorsal, interior, and profile views of the 
shell; 475c, details of sculpture, magnified. 
RiIMvLA GALEATA (Gould). 
Testa solida, cinerea, elevata, globoso-conica, apice centrah, acuto, pror- 
sum porrecto, strus filiformibus confertis radiata, et strits minoribus 
concentricis decussata: fissura brevis, fusiformis: apertura rotun- 
dato-ovalis ; margine expanso, acuto, minutissimé crenulato; fornice 
costa transversali anticé suffulto, fossam trigonalem utroque latere 
formante. 
Rimula galeata, Goutp; Proceed. Boston Soc. Nat. Hist., 11. 159. 
August 1846. Expedition Shells, 14. 
93 
