178 
tinged witli green towards tlie ranboiies, broadly radiated with very 
pale ferruginous and dusky purplish, with numerous dots and ab- 
breviated lines of purple-black: anterior margin with transverse, 
oblique, purple black lines : posterior margin pale ferruginous : 
lunule dusky, bounded by an impressed line : umbones not very 
prominent : hinge margin nearly rectilinear, terminated anteriorly 
by an obtuse angle ; in this part the edge of the left valve laps a 
little over and conceals the corresponding part of the edge of the 
right valve : ligament deeply seated : posterior margin rounded : 
lunule impressed, distinct by an impressed line : within, very 
broadly margined with violaceous ; margin crenated : intermediate 
tooth emarginated at tip : anterior tooth of the left valve also 
emarginated. 
Ohs. This beautiful species was presented to me by the late Mr. 
Stephen Elliott of Charleston, S. Carolina, as an inhabitant of the 
west coast of Mexico. The colored lines on the anterior part of 
the shell, are somewhat like those of V. geographica, Grmel., but 
these lines have a bluish shade forwards, are more regular than in 
the figure of that species in the Encycl. Meth., and as a species it 
widely distinct. 
I have an indistinct recollection of a figure resembling this spe- 
cies, but I cannot recall the work, for the purpose of comparing 
the characters. PL 26. 
SCALARIA. — Shell turrited; volutions convex, gradually in- 
creasing in size to the aperture, with numerous, elevated, longitu- 
dinal ribs or varices ; aperture nearly orbicular, slightly longer than 
broad ; peristome continuous, reflected ; operculum horny, spiral, 
thin. 
Ohs. A genus of very pretty shells, known by the name of 
Staircase shells by some collectors, and with respect to the nature 
of which, naturalists formerly differed much. Favanne and Graul- 
teri and others, believed them to be closely related to Serpula^ and 
Rumphius placed them in his Buccinum. Such as were known to 
Linne he referred to Turho^ on account of the rotundity of the 
aperture. In this respect they certainly also resemble Cydostoma 
and Pupa ; but the elevated ribs distinguish them from the first, 
and the successive and regular increase in the size of the volutions 
separate them from such species of the latter, as have slight rib- 
like elevations. They seem also to approach some species of the 
genus Rissoa in the character of the ribs. 
