WORMS. TESTACEA. 66. Oftrea. 257 
She/i roiindifli, fmoothi flightlyearedand franfverfely/lriatc. 
Inhabit! the Mediterranean ; fize of a: man s nail. 
5 heU poliftied, with undulate rufous marks : the ftna: very fine, 
7 ■ 
“dtus, obliquely ovate, fmoothilh, with a triangular hinge. 
Pennant Brit, Zool.w. tab, 
Barhat, tah, Jjjig, 6 , Gualt.test. /- 83 . R. 
Chemn, conch. 7. tab. 58. fig> 574" a, b. . - f 
Inhabits £«r(;/>r«a feas, and is fometimes found fofiile ; nze 
an haiel nut; covered with an olivaceous skin under which it 
fs white; within filvery : Jhell unequally triangular, with very 
fine perpendicular ftrla: croffed by a few arched tranfverfe 
ones ; deprefliion b. hind the beaks hearc-lhapcd. 
i' 
Shell entirely white, rhomboid heart-fhaped ahd ribbed,- 
the anterior and dorfal ribs knotty : beaks reiriote. 
Lister, tab. 244. fg- 7 S‘ ^ 7 > A. 
Knorr Vergn. tab. figrl. 
Chemn. conch, 7. tab. 56- A?" 553 * . j- . 
Inhabits the Indian and American Ocean ; anterior uope heart- 
fliaped, pollerior one rhomboid. 
"^’’’^raia Shell cqullatera’, thin, flattifti, with very fine decuffate 
ftriaj : beaks approximate ; hinge arched. 
Chemn, conch. 7. tab. 57. fg. 563. , 
•Inhabits the American Ocean : white varied with yellowifli cha- 
taflers ahd fpots. 
Shell ventricofe, with longitudinal flriai ahd lines, and an- 
gular on one fide : beaks approximate : hinge arched. 
Lister conch, tab. 245 * fiS' 7 ^- 
Chemn. conch. 7. tab. 0^7. fig- 5 ^ 7 - , . , 
Inhabits Ihores of Africa znd. American Ocean : brown with a 
few fpots. 
Shell oblong, very much deprefTcd, ftrlate ; beaks very 
nightly prominent. 
Irihabits Qrono'V* Xooph, tah* l8. f*Ji 
(S6. OSTIIEA. Aniviat a Tetliys : Jhell bi- 
valve, generally with unequal valves anti 
nightly' eaved; hinge withput teeth, but 
furnillied with an ovate hollow, and inoft- 
ly lateral tranfverfe grooves; Oyjler. 
VOL. IV. — 'k k Moft 
^^Pba. 
