WILCOX CROUP. 



29 



Querms chlorophylla Losquproux, Am. Philos. Sof. Trans., 

 new spr., vol. i:i, j). 4 Hi, pi. 17. fig. 5. Figure 5 dop.^ 

 not represent thi.s si)ecie!< nor is it determinable. The 

 speeiineius shown in ligiiros G and 7 are referred by me 

 to Minmsops and Pisonia respectively. 



Qucrrus relracta Lesquereux, idem, p. 416, pi. 16, fig. 5. 

 This fragment is undeterminable. The specimen 

 shown in figure 4 has been referred to Myn-ia ht'iUonensis 

 The record from Benton. Ark., given by Harris (op. 

 cit.) is based on material since lost. 



<SaZtx Jfterfm Lesquereux, U. S. Nat. Mus. Proc. vul. 11. p. 

 13, 1888. Recorded from Wickliffe, Ky. Siipcinun 

 lost. 



Sapindus caudalus Lesquereux, idem, ]>. 21. lieronlpd 

 from Cross Bayou, La. Not determinalilc. 



Sapindus coriaceus Lesquereux, idem. PicrcmU'd from 

 Cross Bayou, I-a. Not determinable. 



NOMENCLATUEE. 



The terminology which saiutinus the name 

 Wilco.x for thi.s group of formations is not of 

 long standing, the various iiichided deposits, 

 either individually or collectively having re- 

 ceived many names, ])oth lithologic and geo- 

 grapliic, of differing shades of meaning. As is 

 usually and of necessity the case in geologic 

 studies, most of the earlier names were loosely 

 applied, without precisely defined liniits or 

 adequate lithologic or paleontologic character- 

 istics. It is unnecessary for the purposes of 

 this study to go back farther than 1860, the 

 date of publication of Ililgard's ''Report on 

 the geology and agriculture of Mississippi." 

 In this work the Wilcox and underlying de- 

 posits of the Midway formation in the Missis- 

 sippi area are termed the ''Northern Lignitic 

 group," usually shortened to simply "Lig- 

 nitic."' Not oidy because it is a lithologic 

 term, based on an area where marine faunas 

 are in general absent, but also because it in- 

 cluded younger deposits it has been abandoned 

 in more recent years. It was adopted by 

 Smith - for the Alabama area and well char- 

 acterized in L8S7 with various subdivisions, 

 largely paleontologic, named, in order from the 

 top downward, Hatchetigbeo, Bashi, Tusca- 

 homa, and Nanafalia. In this usage it also in- 

 cluded the underlying Midway. Harris ■' in 

 1894 used "Lignitic" but gave it the restricted 

 paleontologic basis of the Wilcox as used at the 



I nilcard, E. W., Report on thegeology and agriculture of Mississippi, 

 pp. 110-123, IN60. 



sSmith, E. A.,and John.son, L. C, U. S. Geol. Survey Bull. 43, pp. 18, 

 38, 1887, and many subsequent publications of the Alabama Geological 

 Suri'ey. 



' Harris. G. D., Am. Jour. Sci., 3d .sor., vol. 47, p. 304, 1894: Bull. Am. 

 Paleontology, vol. 2, No. 9, 1897. 



pre.sont time. Meanwhih^ .SafTord * in 18.56 and 

 later, ti-s a result of liis studies in western Ten- 

 nessee, liad proposed tlie ttu'in "Orange sand 

 or La Grange: gr()U|)." 



The ttu'in "Orange sand" wtxs afterward 

 used by Hilgard for the deposits in Mississippi 

 subse(iuently referrtnl to the Lafayette forma- 

 tion and not in (he sense of the original pro- 

 poser of the iiaiiie, who uscul it in the sensein 

 which Ililgard uschI "Lignitic." The fact that 

 much if not ail of Ililgard's Orange sand or 

 Lafayt^ttt^ in Mississippi is really of WUeox age 

 flirt lier conipli<'at(w a difTicult rpiestion of 

 taxonomy. Safl'ord's term "Orange sand or 

 La Grange group" is objectionable, because it 

 included surflcial deposits of the so-called 

 Lafayette,-' somt^ Cretaceous materitils, and the 

 younger sands and clays of west Tennessee, which 

 are probably of lower Jackson age. This was 

 in 1864. In 1869 Ililgard " proposed the name 

 "Mansfield group" for the Wilcox of nortli- 

 western Louisiana. This uint was, however, 

 without a paleontologic basis and of less extent 

 than the Wilco.x as now defined. The "Cam- 

 den series," proposed ]>y Ilill ' in 1888, included 

 not only Ililgard's Manslield but Cretaceous 

 and Jackson deposits. Meanwhile Heilprin * 

 had proposed the term "Eolignitic," which is 

 open to the same objections as the term "Lig- 

 nitic," and, unlike that term, lias never been 

 accorded a very extensive usage. Dall " in 

 1898 adopted the term "Chickasaw or Cliicka- 

 sawan stage," proposed by Hilgard'" in 1871 

 as the ecpiivalent of his "Northern Lignitic," 

 assuming that the "Lignitic" as delined by 

 Hilgard was the exact equivalent of the 

 "Lignitic" of southern Alabama. As it em- 

 braces younger Eocene deposits, especially at 

 the supposed type locality of the Chickasaw 

 BlufTs, and is thus historically inappropriate, 

 it also has been al)aiuloneiL 



In 1906 Veatch " proposed the name "Sa- 

 bine," because of the development of a marine 

 fossiliferous series of outcrops tilong Sal)ine 



» Saflord, J. M., Am. Jour. Sci., 2d ser., vol. 37, pp. 369-370, 1864. 



'• Hilgard, E. W., and Saflord, J. M.. communication in .\m. (ieolo- 

 gLst, vol. S, pp. 129-131, 1S91. 



6 Ililgard, E. W., Am. Jour. .Sci., 2d .ser., vol. 48, p. 340, 18B9. 



' Uill, It. T., Arkansas Geol. Survey Kept, for 1888, vol. 2, pp. 49-53, 

 1888. 



8 Heilprin. .Vngelo, Contributions lo tlie Tertiary geology and paleon- 

 tology of the tTnitcd State-s, Pbiladelphia, 1884. 



5 Dall, W. II., U. S. Geol. Survey Eighteenth Ann. Kept., pt. 2, table 

 opp. p. 334, 1S98. 



i» Ililgiird, E. W., Am. .Tour. Sci., 3d .ser., vol. 2, pp. 391-.396, 1871. 



■1 Veatch, A. C, U. S. Geol. Survey Prof. Paper 46, pp. 34-3(i, 1906. 



