95 MOI.I.USCA OF THE GuivF OF MEXICO 63 



Holmes, Post-Pl. Fos. S. C, p. 24, pi. 5, f. 3, '60; 

 Dall, Bull. 37, U. S. N. M., p. 52, '89 ; Singley, 4th 

 Ann. Rept. Tex., p. 327, '92 ; Dall, Tr. W. I. S., 3, p. 

 1089, 1900 ; Vanatta, Proc. A. N. S. Phila., 55, j). 757, '03. 

 Not of Tuome}' and Holme.s, 1857. 



campechiense Bolten, Miis. Bolt., p. 191, 1798; gosseiX)^'^- 

 hayes, 1854 ; csquilaterale Hilgard. 1878. 

 Distribution. — Hatteras to Brazil. Usually very shallow water. 

 Pleistocene to Recent. Gulf coast. — Indian Pass, St. Jo- 

 seph's Bay, Fla. ; Chandeleurs, La. ; Galveston, Corpus 

 Christi and Espiritu Santo Bays, Tex., Campeche, (type 

 localit}'). Pleistocene : New Orleans pumping station 

 No. 7, Lake Borgue borings, ( Hilgard' s cequilaterale) . 

 (Cerastoderma) robustum Solander, Portland Cat., p. 58, 1786, 

 Dall, Tr. W. I. S., 3, p. 1099, 1900 ; Proc. U. S. N. M., 

 23, p. 386, '01 ; Vanatta, P. A. N. S., Phila., 55, p. 757, 

 '03 ; Vaughan, 2d Ann. Rept. Fla. Surv., p. 149, 1909. 



ventricosum Bruguiere, Ency. Meth. I, p. 228, 1789. 



magmim Born, Ind. Mus. Vind., p. 34; Test. Mus. Vind., 

 p. 46, pi. 3, fig. 5, 1780 ; Reeve. Conch. Icon. 2, 

 Cardiian, pi. 4, f. 20, 1844 ; Holmes, Post-Pl. Fos. S. C, 

 p. 23, pi. 5, f. 2, 2 a, '60; Hilgard, Rept. Chief of Engineers 

 to Sec. of War, p. 358, 1S70 ; Dall, Bull. 37, U. S. N. 

 M., p. 52, '89 ; Singley, 4th Ann. Rept. Tex., p. 327, '92; 

 Harris, Bull. Am. Pal. vol. i, p. 91, '95; Mitchell, List 

 Texas Sh. Not magnum Linnaeus, Syst. Nat., ed. X, p. 

 680, 1758. 



incequilaterale Hilgard, House of Rep. Ex. Doc. i, pt. 2, p. 

 889, 1878. 

 Distribution. — New Jersey to Campeche. Upper Miocene to 

 Recent. Gulf coast. — Recent : Ft. Barranca, St. Mark's, 

 St. Andrew's Ba}', Indian Pass, Crooked Island, Fla. ; 

 Horn Island, Miss. ; Cameron, Chandeleurs, La. ; Galves- 

 ton, Padre Lsland, Corpus Christi, Tex. Pleistocene : La- 

 belle, Osprey and Manatee, Fla. ; New Orleans well of 

 1856 at 41 feet, Grand Chenier, Lake Borgne borings (?)> 



