64 



the thickness of the lateral teeth ; it is also shorter in 

 proportion to the height. 



Found at Long Branch, New Jersey, by William 

 S. Warder. 



MACTRA SOLIDISSIMA. 



Tab. XIV, /^. 7, and Tab. XV. 



SPECIFIC CHARACTER. 



Shell large, solid, subovate or subtriangular ; car- 

 dinal fosset very large, cordate ; lateral teeth trans- 

 versely striated ; muscular impressions very large. 



SYNONYMES. 



Mactra SOLIDISSIMA, Chem. Dill, Wood, Index 



Test:^^pl. 6, fig. 22. 

 M. soLiDA, Var. B. Gmel. 

 M. PROCERA, Solander, 



M. GRANDis, Soland. Wood, Index Test. pi. 6,/. 19. 

 M. GiGANTEA, Lam. *6in. sans vert. vol. 5, p. 472. 

 M. siMiLis, Sai/, Journ. Acad. JVat. Sciences, vol. 2, 



p. 309. 



OBSERVATIONS. 



This is much the largest species known, measuring 

 seven inches in length. 



