47 MOLLl'SCA OP THE GuLF OF MEXICO I5 



Subgenus NOETIA Gray 



Nodia ponderosa Say 



Area pond erosa'S2i\\ Jour, Acad. Nat, Sci. Phila,, ist. ser., 

 vol. 2, p. 267, 1822. 



contraria Reeve, Conch. Icon., Area, pL S, fig, 55, 1844. 



elegans Philij^pi, Zeitschr. Mai., p. 92, 1847. Not elci^ans 

 of Perry, 181 1 ; Roemer, 1836; d'Orbigny, 1844; Wood, 

 1846 ; nor of de Kominck. 

 ponderosa Holmes, Post-Pleiocene Fos, S. Car., p. 21, pi. 4, 



fig.s. 4, 4a, i860; Hilgard, House of Rep. Ex. Doc, vol. 



I, pt. 2, p. 887, 1878 ; Singley, Fourth Ann, Rept. Geol. 



Surv. Texas, p. 325, 1892. 



{Noetia) ponderosa Dall, Bull. 37, U. S. Nat. Mus., p. 40, 

 1889 ; Trans. Wagner Inst. Sci., vol. 3, pt. 4, p. 633, 

 1898 ; Vanatta, Proc. Acad, Nat. Sci. Phila., vol. 55, p. 

 756, 1903 : Clark, Maryland Geol. Surv., Pleistocene, p. 

 205, pi. 64, figs. 1-6, 1906 ; Sheldon, Palseont. Amer., 

 vol. I, p. 28, pi. 6, figs. 6-10, 1916. 



Distribution. — Cape Cod to Yucatan. Pliocine to Recent. 

 Gulf Coast. — Recent : Ft. Barranca, Cedar Keys, Indian 

 Pass, St. Joseph's Bay, Crooked Island, Florida : Horn 

 Island, Mississippi ; Point au Fer, Louisiana ; Galveston, 

 Corpus Christi, Texas. 



Pleistocene : Grand Chenier, New Orleans pumping station 

 No. 7, New Orleans artesian well of 1856 at 480 and 560 

 feet (Hilgard), Lake Borgne borings; Knapp's wells, Ter- 

 rebonne Parish, No. 2, at 1519-1542, 1632-1726, 1719- 

 1842, No. 3 at 670, 1 579-1618, 1700, Crowley well No. 4, 

 Jennings, at 1663- 1670 feet. 



Upper Miocene : variety carolinensis Conrad, Galveston artes- 

 ian well at 2552-2871 feet (Harris). 



