154 SOLENIDAL. 
Pholades. 1 believe there is no communication between the 
siphons, but I have not proved this fact by injections, as in 
Pholas. The branchial transverse vessels, artery, and vem 
are very distinctly marked; there are, im connection with the 
lamin, a pair, on each side, of pale brown, thin, small, 
delicate triangular palpi, smooth without, striated within. 
The liver is composed of distinct aggregations of lght 
greenish or yellowish masses, with the ovary united to it 
more anteally. The crystalline stylet is very long, but the 
tricuspid membrane or attritor is without much consistence ; 
it works, however, in the stomach. The general anatomy 
is In most respects as in Pholas, but it has two adductors, 
instead of the single post-medial one of that genus, and, as 
in it, the intestine plunges into the body, then ascends, and 
runs posteriorly on the dorsal range embraced by the heart 
and auricles, and discharges into the anal conduit by a white 
pendulous rectum. The branchial and anal siphons being 
short, may possibly be confluent as in the short-tubed animals, 
in which case the entire ventral cavity must be considered 
as one large branchial siphon, divided by a septum at their 
termination. 
This animal represents the typical Solens. We may observe, 
that the long branchial cavity in some measure supplies the 
place of the elongated siphons of the Pholades. 
S. PELLUcIDUs, Pennant et Auct. 
S. pellucidus, Brit. Moll. i. p. 252, pl. 13. f. 3; (animal) pl. I. f. 2. 
Animal elongated, compressed ; mantle of the palest drab, 
closed ventrally, without the central assistant branchial slit 
as in S. séligua, open at both ends for the passage of the foot 
and siphons; these latter are very short, scarcely protruded 
beyond the shell; the branchial has about ten cirrhi, edged 
with fine brown lines, with one or two smaller ones between 
each ; the anal tube is plam, or scarcely broken into points of 
a pale brown, and on both are a few large, rather long, white 
filaments, sprmging from the body of the common sheath, 
just below the siphonal orifices. The foot is much less 
