WORMS. TESTACEA. 66. Oftrea. 277 



farafitUa. Shell thin ; lower-valve convex and thicker, the other flat. 

 Rumpf. Muf. tab, 46. O. Klein Oftr. tab. 8. /. 17. 

 Peti°v, Amb. tab, 19. fig. II. 

 Chemn. conch. 8. tab. 74.. fig- 681. 



2. Adanf Seneg. I. /*£. 14. fig- l- 



3. Cbemn conch. 9 /*£. n6.//£. 997. 



Inhabits the Indian and Atlantic Teas, and fixes itfelf to the roots 

 and Humps of trees growing clofe to and hanging over the wa- 

 ter, efpecially the Mangifera ; varies in form and fize, but is 

 often as large as the pa:m of the hand. 



Exalbida, ^^W thin, the upper-valve longer and more convex. 



KnorrVergn. 5. tab. %%+Jig* 3» 4- 



Inhabits the Adriatic* and is found fixed toother (hells fometimes 

 alone fometimes feyeral together; about 1 \ inch long, but is 

 variable as to fhape and fize ; generally whitifh, rarely yellow 

 or violet, 



QtiBatq, S}iell rugged, with imbricate lamellae-: the margin with 

 obtufely plaited teeth: the beak of one valve produced. 



Born, fouf. Caf. Find. te/t. 1. tab. 7. fig. 3. 



Inhabits Shell an inch long and jo. lines broad, white with 



a few black fpots : hinge with a broad conic tooth in the 

 middle. 



Smgalenfis Shell equivalve roundifh fmooth flat. 

 Adans Jeneg. i. tab. l^fig- $■ 



Inhabits mores of Senegal, and adheres to rocks; about 2 inches 

 in diameter: tawny, within whitifh. 



Stellata* Shell thin depreffed rough unequal ; the upper T valve ribbed, 

 the ribs with a few fpines. 

 SchrcEt. Einl. in Conch. 3. tab. 9 fig. 7. a, b. 

 Inhabits Guinea, and is found afrixed to other bodies by the 

 hinge: fometimes round fometimes oblong; very thin, white 

 with red or blucifh rays fpots or marks. 



Oralis. Shell oval very thin and terminating in a fhort acute lateral 



channelled beak ; with obfolete unequal perpendicular 



ftriie. 

 Shra?t. Einl. in conch. 8. tab. t)-fig> 8. 

 Inhabits Shell about an inch long, brittle, whitifh, within 



gloffy filver-white : lower -valve exceeding the upper both in 



length and breadth. 



Patyrjtcea. Shell roundifh fnowy very thin pellucid j upper- valve ter- 

 minating in a Ihort acute beak. 



Schrcs, 



