131 Mollusc A of the Gulf op Mexico 99 



European Ensis ensis of Linnaeus, 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 Ba}^, Laguna Madre, Texas. 

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

 3- P- 955. 1900. 

 Sol 671 ensis, "small variety", Conrad, 183 1. 



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. ii, 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. Sh., p. 16. 

 ovalina Lamarck, of authors. 

 oblo7iga Say, Jour. A. N. S. Phila., 2, p. 310, 1822 ; oblon- 



^a/<xRavenel, 1834 ; bilineata (C. B. Adams) Reeve, 1854 5 



silicula Reeve, 1854, not of Deshayes. 

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



1875- 

 Distribution. — 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 vSanto Bays, Texas. Pleistocene : 



