MARYLAND GEOLOGICAL SURVEY 209 



ECPHORA QUADRICOSTATA VAR. UMBILICATA (Wagner). 



Plate LII, Fig. 4. 



Fusus umbilicus Wagner, 1839, Plate 3, Hg. 2. 



Fiisus quadricostatus Conrad, 1842, Proc. Nat. [nst.. Bull, ii, p. 185. 



Fusus quadricosiatus Bronn, 1848, Hand. Gesch. Nat., Index Pal., pt. i, p. .517. 



Fusiis quadricosiatus var. umbilicaius Bronn, 1849, Hand. Gesch. Nat., Index Pal., 



pt. ii, p. 4.55. 

 Ecphora quadricostata Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, p. 27. (Not 



pp. 24, 28.) 

 Ecphora quadricostata var. Dall, 1898, Trans. Wagner Free Inst. Sci., vol. v. No. 2, 



p. 9. 



Description. — This variety differs from the typical forms of the species 

 in having a thinner shell, a more Haring umbilicus, more loosely coiled 

 whorls, and ribs which are not T-shaped. Because of the thinner shell, 

 the looser coiling, and the lithologic character of the formation in which 

 the variety occurs, perfect specimens are far rarer than those of the typical 

 quadricostata and the distinctness of the variety has not been generally 

 recognized. The figure prepared by Wagner in 1839 was on one of those 

 plates which were not regularly published until 1898, but of which a few 

 copies were distributed with manuscript names attached.^ Apparently 

 no description of var. umhilicata has ever been published till now. 



There are specimens of this variety in the National Museum from Alum 

 BlufP, Fla. (upper bed). 



Length, 70 mm. ; diameter, 60 mm. 



Occurrence. — Choptank Formation. Jones Wharf, Dover Bridge, 3 

 miles south of Governor Eun (lower bed). Governor Eun (lower bed), 

 Flag Pond, Pawpaw Point, Governor Eun (upper bed), Greensboro, Cor- 

 dova. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Cornell University, U. S. National Museum. 



Ecphora tricostata n. sp. 



Plate LIT, Figs. 5, 6, 7, 8. 



Description. — Shell of moderate size, thin, chitinous, loosely coiled, 

 six-whorled; nucleus smooth, elevated, conical, three-whorled ; spire sharp, 



1 Dall, Trans. Wagner Free Inst. Sci., vol. v. No. 2, p. 9. 

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