168 
from tlie apex to the basal margin. S. radiatus, Linn. (G-enns 
Siliqua, Megerle ; Leguminaria, Schum.) 
B. More cylindric and destitute of the interior rib. 8 . strigilla- 
tus, Linn. 
C. More elongated and subcylindric. S. legumen, Linn. 
These species shew the connection of the two genera to be inti- 
mate ) but there is certainly a great difference in habit, which, in 
conjunction with the notable characters of the rounded form of 
the muscular impressions, the distance of the hinge from the ex- 
tremity, &c., in the present group, seem to justify its separation 
from Bolen. Like the species of that genus, these reside in the 
sand on the sea shores, secluded from observation. 
SoLECURTUS COSTATTJS. — ■ Specific character. Hinge nearly 
equidistant from the posterior termination of the shell and the mid- 
dle of the hinge margin. PI. 18. 
Solen costatus, nohis. Journ. Acad. Nat. Sci. vol. 2, p. 315. 
Fulgur. — -Shell pyriform ; spire very short varices none ; body 
whorl very large aperture large, oval, extended towards the base 
into an elongate conic, open canal, which is entire at base ; um- 
bilicus none ; epidermis deciduous ; labium concave with a single 
fold or oblique groove near the origin of the canal and a slight 
calcareous deposition above ; labrum simple : within having eleva- 
ted striae which do not revolve far within the shell, nor do they 
reach the edge of the labrum, but leave a smooth border ; opercu- 
lum horny. 
Ohs. This genus was formed by Montfort. Linne placed all 
the species with which he was acquainted in his great genus Murex. 
Bruguieres, Lamarck and Blainville referred them to Pyrida, a 
genus with which they are certainly very closely allied, but from 
which they differ in having a fold on the labium, in not being 
vesicular and thin, in having elevated lines or strise within the 
labrum, &c. Linne did not even perceive this alliance, if we may 
judge from the fact that he placed these shells with Murex, as 
above stated, whilst he referred the true Pyrulse to his reservoir 
Bulla. We do not know what difference exists between the ani- 
mals. Naturalists do not appear to know whether or not they are 
operculated, but we can affirm with certainty that the operculum 
exists in the present genus. When recent the surface of the shell 
