42 
posed. I conceive that all those in Martin’s division of 
Anomitce d. d. (Martins’s outlines, &c. p. 24 3.) which he 
describes as having both valves convex, and a large tri- 
gonal foramen belong to this Genus, and also, perhaps, 
those of his next section with a small foramen, but we 
are not sufficiently acquainted with their internal struc- 
ture, to decide whether another Genus may not be neces- 
sary to render the divisions of the Linnean Genus Ano- 
mia quite natural. 
SPIRIFER cuspidatus. 
Spec. Char. Inversely pyramidal, longitudi- 
nally sulcated; back fiat, triangular, equila- 
teral; front elevated by a semicircular sinus, 
corresponding to a large longitudinal rising in 
the upper, and depression in the lower valve. 
Syn. Anomia cusp i data. W. Martin in Trans ; 
of Linn. Soc. IV. p. 45. t. 3. 
and t. 4 .fig. 5. Petrif. Herb, 
t. 46. ^47. fig. 3. 4. and 5. 
Terebratula. Parkinson Org. Rem. Ill . 
234. t. 16. Jig. 17. 
Deeper valve nearly flat at the back, because its beak is 
but slightly incurved, or is straight, and sometimes even 
it is recurved; its depth is equal to its greatest width, 
which is occupied by the line of the hinge; the other 
valve is about one third the depth : the length is equal to 
about one half the width; the edge semicircular; there 
