EUN ax 
A 
T 
w certainty. 
» 
JO Neve having seen the shells themselves, however, it 
, of course, out of my power to. decide this point with 
Genus scam Schumacher. 
inent CHARACTERS. Shell very thit and bi 
transversely oblong, inequivalve, corbuliform, rig 
the more convex, very equilateral, posterior s e short 
subtruncated, and but slightly gaping, hinge edentu i 
an oblique, projecting, spoon-shaped process on each 
valve forms with the anterior cardinal'edge a deep sinus, 
jn which is inserted a. flat ossiculum, of a semicircular 
or sub-triangular shape, retained in its position by a small - 
portion of the ligament, which is double, the external 
portion anterior, very thin or membranous, the internal 
strong and contained in the cardinal processes.  Mus- 
cular impressions remote, anterior long and narrow near 
the cardinal edge, posterior small and rounded ; palleal 
impression deeply indented pail. Interior sub- 
perlaceous. ` = 
PrripLoma TRAPEZOIDES. 
P. testi rotundato-quadratà, conyexA, tenui, pellacida, levigata, 
dente cochleari obliquato. mee en 
Cürbala. Ency. Meth. tab. 930, v2 6, a. b 
Anatina trapezoides, Lax., Anim. sans Vert: edit. 
1818, V. p. 464. 
Periplóma. inequivàlvis, ScmuwacH. Essai d'une 
Syst. de Conch. p. 115, tab. 5, f. 1, a. b 
