24 TESTACEOUS MOLLUSCA. 
end ; white, nearly smooth ; shorter side a little gaping and with 
a longitudinal wave ; tooth long, narrow, very oblique. %..43.— 
U. States. Ossiculum not unlike two creseents joined at the ex- 
tremities. 
A Leana. Conr. Jour. A. N.S. Phil. 6. t. 11. f. 11.— 
CocutopesmMA L. Gould. Mas. f. 29, 30. Inequivalve, ellip- 
tical, subeompressed, very thin and fragile, white with a yellowish 
slightly polished epidermis, posteriorly rather shorter and slightly 
more obtuse, with a linear gape; margin waved, beaks very small. 
41.—U. States. 
A. Eroneata. Stutch. Z. J. 5. t. sup. 43. f. 9, 10. Trans- 
versely elongated, inequivalve, inequilateral, pellucid, sinus of the 
palleal scar elongated towards the anterior side. =3,..3. 
A. Brevis. Stutch. Z. J. 5. p. 99. t. sup. 43. f. 1, 2. —Pan- 
pora B. Sow. Plano-convex, subtriangular, transversely striated ; 
one valve convex, with two depressed transversely lamellated ribs on 
the posterior extremity, the other slightly concave, the dorsal edge 
inflected and inserted into a sulcus in the opposite valve; hinge with 
an internal triangular cartilage, and a supervening shelly piece; 
umbo reflected posteriorly. 2,.3.1 
* Can these four last shells be justly considered Anatinee ? 
Deshayes in his new edition of Lamare introduces the genus 
Osteopoma, which he thus characterises : Oblong, transverse, tri- 
angular, thin, inequivalve, shghtly gaping at its extremities ; hinge 
linear, having on each valve a very narrow apophysis, firmly adherent 
along the dorsal edge of the valves, and a quadrangular shelly sub- 
stance kept between them by the ligament, to which its entire upper 
surface adheres : muscular impressions small, the posterior one elon- 
gated, the anterior rounded: palleal scar excavated posteriorly. 
O. CorsuLoipEs.* Desh.—Mya Norweeica. Gmel. 3222. 
D. p. 48.—Ch. f. 1647, 8.—W. t. 2. f.13.—Tur. Biv. t. 3. f. 6, 
7. Ovate-oblong, rounded at one end, waved and truncated at the 
other ; thin, inequivalve, semitransparent, white under a brown 
epidermis, finely striated concentrically, beaks usually decorticated. 
3..1.—N. Europe. 
O. Sotemyauis. Desh.—Mya 8. Lam. 4. Transversely ob- 
long, white, obtuse at the extremities, slightly gaping anteriorly, the 
posterior side very short, the anterior more produced and obliquely 
rayed. Wants but the hinge to make it a Solemya.— New Holland. 
O.Hyattna. Couthouy.—Gould Mas. f.10.—Mya H. Conr. 
Jour. A. N.S. Phil. 6. t. 11. f. 12.—Lyonsta H. Conrad. Am. 
C. t.11.f.2. Oblong, extremely thin, fragile, pellucid, posteriorly 
short and rounded, anteriorly produced, attenuated, slightly reflected 
and truncated at the extremity, epidermis pale with radiating rugose 
