MACTRA. 



73 



at one margin a delicate, erect tooth like the letter V ; two lat- 

 eral teeth near the central ones. Animal with the mantle open 

 to the siphons, fringed ; siphons fringed ; foot kneed ; outer bran- 

 chial leaflet shortest. 



Mactra solidissima. 



Shell large, massive, strong, oval, covered with a dirty-brown epidermis, sub- 

 equipartite; hinge strong, V tooth dehcate; paUial impressions slightly indented 

 posteriorly. 



Mactra solidissima, Chemn., Conch, x. 350, t, 170, fig. 1656 (hinge). — Dillwyn, Catal. 



i. 140. — Wood, Index, pi. 6, fig. 22. — Conrad, Amcr. Mar. Conch. 64, pi. 14, 



fii,^ 7.— PiiiLiPPi, Abbild. t. 1, fig. 2. — Stimi»son, Shells of New England, 20; 



Invert. Gr. Manan, 21. — De K.vy, Nat. Hist. New York, 229, pi. 29, fig. 286. 

 Mactra fjicjantm, L.\.m., An. sans Vert. vi. 97. — Desiiayes, Encyc. Mc'th. Vers, ii. .394, 



pi. 259, fig. 1 (18.30). — Chenu, 111. Conch, pi. 1, fig. 2; Man. do Conch, ii. 56, fig. 



231. — MiGHELS, Best. Jonrn. Nat. Hist. iv. 315. 

 Mactra luteola, Lovex, MSS. (yonng). 

 Mactra ponderosa, Philipi'I, Abbild. t. 1, fig. 1 (1844). 



Shell very large and solid, transversely ovate, somewhat trian- 

 gular, nearly equipartite, anteriorly a little the shortest, and with 



Fig. 387. 



"^Vc 



a fissure between the beaks ; surface slightly folded at the lines of 

 growth, covered with a thin, dirty-brown or straw-colored epider- 



