132 



4£ttlM VIII. 



MACTRA: 



SHELL BIVALVE, WITH THE SIDES UNEQUAL, AND 

 THE VALVES EQUAL. HINGE WITH THE MIDDLE 

 TOOTH COMPLICATED, AND AN ADJACENT CAVITY ; 

 LATERAL TEETH REMOTE, AND INSERTED INTO 

 THE OPPOSITE VALVE. 





Shells sub-triangular. 

 Shells ovate-oblong. 



Shells sub-triangular. 



o 



spengleri. 1. Shell smooth, with the anterior 

 slope flat, and a transverse crescent-shaped 

 gap by the cartilage. 



Mactra Spengleri. Linnaus Syst. Nat. p. 1125. Chem- 

 nitz, vi. p. 209. t. 20. f. 199 to 201. Schroeter Einl.m. 

 p. 72. Gmelin, p. 3256. 

 Regenfuss, ii. t. 11. f. 49- Enc. Method, t. 252. f. 3. 



Inhabits the Cape of Good Hope. Spengler. 



Shell two inches long, near three inches broad, and an inch 

 and a quarter high; somewhat triangular, sub-diaphanous, 

 smooth, and of a pale brownish colour, often becoming red- 

 dish towards the margin ; the posterior slope is flattish, but 

 not so much so as the other, and the hinge is central. From 

 Born's description it is probable that he mistook M. striatn- 

 la for this species. 



plicataria. 2. Shell transversely plaited, diapha- 

 nous, and brittle; anterior margin flattish, 

 and the posterior depression oblong. 



