PLATE CXXVf. 



MACTRA SUBTRUNCTA. 



SUBTRUNCATED MACTRA, 



GENERIC CHARACTER. 



Animal a Tethys. Bivalve, sides unequal. Middle tooth complicated, 

 with a little groove on each side : lateral teeth remote. 



SPECIFIC CHARACTER 



AND 



SYNONYMS. 



Shell somewhat triangular, whitish, smooth, subtruncated on 



each side. 



Mactra subtruncata : testa subtriangularis, albescens, laevis 



lateribus subtruncatis. 

 Trigonella albescens lsevis, lateribus subtruncatis. Subtruncata. D(i 



Costa. Brit. Couch, p. 198. No. 34. 



A thick, strong, and heavy shell, of a somewhat triangular shape, 

 and much flattened on each side, obliquely from the beaks : the 

 valves rather convex, the beaks pointed strong, and turned inwards. 



