BRACmOPODA. 59 



As long as our knowledge of the interior characters of Lingulella is limited 

 to the few species cited, the genus may tentatively include such forms as have 

 shown the high cardinal area and the distinct pedicle-slit. It is, however, in 

 a broad sense, characteristic of the first or primordial faunas, and it has not 

 been satisfactorily demonstrated that any species outside these faunas can be 

 safely referred to the genus. Lingulella loivensis, (Owen) Whitfield, is a proper 

 LiNGULA ; Lingulella Cincinnatiensis, Hall and Whitfield, probably belongs to the 

 same genus. The Lingula paliformis. Hall, of the Hamilton shales, has a distinct 

 cardinal area, an apparently sharply defined pedicle-slit, with faint linear muscu- 

 lar or septal scars. It does not appear to be a true Lingula, and, with our present 

 knowledge, it is impossible to discover wherein it differs from Lingulella. 



This genus has proved much more abundant in American than in European 

 faunas, but of the twenty-five or more species which have appeared in American 

 literature under this generic designation, fully two-fifths should be eliminated ; 

 while, on the other hand, some species passing current under the genus Lingula 

 may eventually prove to be Lingulella. 



Genus LINGULEPIS, Hall. 1863. 



PLATE I, FIGS. 35,36. 



1847. Lingula, (Conkad) Hall. Palseontology N. Y., vol. i, p. 3, pL i, fig. 3. 



1851. TAngula, Hall. Foster and Whitney's Rept. Geol. Lake Superior, p. 204, pL x.\iii, fig-. 2. 



1852. Lingula, Owen. Kept. GeoL Surv. Wisconsin, Iowa and Minnesota, p. 583, pL ib, figs. 4, 6, 8. 

 1863. Lingidepis, Hall. Sixteenth Rept. N. Y. State Cab. Nat. Hist., p. 129, pL vi, fig-s. 12-16. 

 1875. Lingidepi!:, Whitfield. Ludlow's Rept. Reconnais. Black Hills, p. 103. 



(?) 1876. Lingidepis, N. H. Winchell. Fourth Ann. Rept. Geological Survey of Minnesota, p. 41, fig. 6.' 



1877. Lingidepis, Hall and Whitfield. King's Rept. U. S. Expl. Fortieth Parallel, pp. 206, 207, 232. 



1877. Lingidepis, Whitfield. Prelim. Rept. Palfeontology Black Hills, i;ip. S, .9, pi. ii, figs. 5-9. 



1882. Lingidepis, Whitfield. Geology of Wisconsin, vol. iv, p. 109, pi. i, figs. 1, 2. 



1884. Liiiguh-pis, Whitfield. Bull. American Museum of Natural History, vol. i. No. 5, p. 141. 



" Shells linguloid, inequivalve, equilateral, oval-ovate or spatulate ; muscular 

 impression in one valve, flabelliform ; in the other, tripartite, the lateral divi- 

 sions larger. Shell corneous, phosphatic."* 



Type, Li?igula pinniformis, Owen. 



Since the original description of this genus, little has been added to our 

 knowledge of its characters. The number of species that can be assigned to 



* Hall. Sixteenth Report New York State Cabinet of Natural History, p. 126. 1863. 



