22^> 



trim xiii. 



ARCA: 



SHELL BIVALVE, AND THE VALVES EQUAL ; HINGE 

 WITH NUMEROUS ACUTE TEETH, ALTERNATELY 

 INSERTED BETWEEN EACH OTHER. 



Subdivisions, f 



* With the teeth in a straight line. 

 ** With the teeth in a curved line. 

 *## \yjth the teeth in a broken line. 



* With the teeth in a straight line. 



tortuosa. ] . Shell parallelopiped, distorted, with 

 the valves and sides unequal, and obliquely 

 keeled. 



Area tortuosa. Linn&us Syst. Nat. p. 1140. Born Mm. 



p. 87. Chemnitz, vii. p. 168. t. 53. f. 524 and 525. 



Schroeter EinL iii. p. 258. Gmelin, p. 3305. Barbnt, 



t. 49. t. 7. f. 1. Bruguiere Enc. Meth. p. 96. 

 JBonanni Rec. Supp. f. 27 and 28, and Kirch. 2. f. 122 and 



123. Rumphius, t. 47. f. K. Pettier Amb. t. 20. f. 9. 



Gualter, t. 95. f. B. Jrgenvitle, t. 19. f. I. Klein 



Ost. t. 8. f. 16. Knorr, i. t. 23. f. 3. Favanne, t. 51. 



f. G 2. Enc. Meth. t. 305. f. 1. 

 Inhabits the Asiatic Seas. Bonanni. Amboyna. Rumphius, 



f I have adopted Bruguiere's subdivisions which are much better defined, 

 and more simple than those used by Linnaeus. Besides some other of Gmelin's 

 species which are elsewhere mentioned, his A.palchella, p. 3308. and A. lata, p, 

 3312. are undeserving of notice, and A.fossilis is a fossil, as the name implies. 



VOL.1. Q 



