131 MOLI.USCA OF THE GuLF OF MEXICO 99 



European E7isis eftsi's of Linngens, with which it was at 

 first confused. Mitchell, who has studied the habits of 

 this shell on the Texan coast, finds that it lives in a cell 

 about four inches deep. 



Distribution. — Labrador to Florida Keys, 0-25 fms. Miocene 

 (Oak Grove, Fla.) to Recent. Gulf coast.— Cedar Keys, 

 Crooked Isl., Fla. ; Cameron, Chandeleurs, La. ; Corpus 

 Christi, Matagorda Bay, Laguna Madre, Texas. 

 minor Ball, Proc. U. S. N. M., 22, p. 108, 1899 ; Tr. W. L S., 

 3, P- 955. 1900. 

 Solen ensis, "small variety", Conrad, 1831. 



Distribution — Cape May, New Jersey, to Texas. Pleistocene 

 to Recent. Gulf coast. — Cedar Keys, St. Mark's, Fla. ; 

 Matagorda and Corpus Christi bays, Tex. 



Genus MACTRA Linnaeus 

 (Mactrotoma) fragilis Gmelin, Syst. Nat., p. 3261, No. 22, 1792 ; 



Reeve, Conch. Icon., 8, pi. 11, f. 47, 1854 ; Dall, Proc. U. 



S. N. M., 6, p. 338, 1883 ; Nautilus, 8, p. 26, 1894 ; Proc- 



Malacological Soc, i, p. 211, 1895 ; Tr. W. I. S. 3, p. 



894, pi. 27, f. I, 4, 8, 18, 1898. Not Spisula fragilis 



Gray, 1838. 

 dealbata Pulteney, 1803. 

 braziliana Lamarck, An. s. Vert., 5, p. 478, 1818 ; Dall, 



Bull. 37, U. S. N. M., p. 62, 1889; Singley, 4th Ann. 



Rept. Tex., 1892 ; Mitchell, List Tex. vSh., p. 16. 

 ovalina Lamarck, of authors. 



oblonga Say, Jour. A. N. S. Phila., 2, p. 310, 1822 ; oblon- 

 ^^■a/a Ravenel, 1834 ; bilincata (C. B. Adams) Reeve, 1854 '- 



siliada Reeve, 1854, not of Deshayes. 

 anserina Guppy, Ann. Mag. Nat. Hist. 15, p. 50, pi. 7, f. i. 



1875- 

 Di.stribution. — Hatteras to Rio de Janeiro, also cited from 

 west coast of Africa. Pliocene to Recent. Gulf coast. — 

 Recent : Cedar Keys, Fla. ; Corpus Christi, Carancahua, 

 Matagorda, and Espiritu Santo Bays, Texas. Pleistocene : 



