546 CAilBRIAN BRAGHIOPODA. 



Lingula anliqua Emmons, Hall, 1851, Kept. Geology Lake Superior Land District, by Foster and Whitney, pt. 2, 



pp. 204-205, PI. XXIII, figs. 2a-c. (Discussed; ventral valves.) 

 Lingula pinnaformis Owen, 1852, Kept. Geol. Survey Wisconsin, Iowa, and Minnesota, p. 583, PI. Ib, figs. 4, 6, and 8. 



(Described.) 

 Lingula antiqua Emmons, Hall, 1862, Kept. Geol. Survey Wisconsin, vol. 1, fig. 2, p. 21. (No text reference.) 

 Lingula pinnseformis Owen, Hall, 1862, idem, p. 435, fig. 3, p. 21. (Discussed.) 

 Lingula antiqua Emmons, Hayden, 1862, Am. Jour. Sci., 2d ser., vol. 33, p. 73, figs. la-b. (Discussed. It may be 



that the Lingula prima here mentioned by Hayden was based on the dorsal valves of L. antiqua.) 

 Lingulepis pinnaformis (Owen), Hall (in part), 1863, Sixteenth Rept. New York State Cab. Nat. Hist., pp. 129- 



130, PL VI, figs. 14-16 (not figs. 12 and 13, referred to Obolus matinalis). (Described and discussed.) 

 Lingulepis pinnijormis (Owen), Meek and Hayden, 1865, Smithsonian Contrib. KnowL, No. 172, Paleontology 



Upper Missouri, pp. 2-3, PL I, figs. la-b. (Described and discussed.) 

 Lingulepis dakotensis Meek and Hayden, 1865, idem, p. 3. (Name merely proposed in case the species should prove 



distinct.) 

 Lingulepis pinnaformis (Owen), Hall (in part), 1867, Trans. Albany Inst., vol. 5, p. 107, PL I, figs. 14-16 (not 



figs. 12 and 13, referred to Obolus matinalis). (Copy of Hall, 1863, p. 129-130.) 

 Lingulepis pinnaformis (Owen), Whitfield, 1880, U. S. Geog. and Geol. Survey Rocky Mtn. Region, Rept. Geology 



and Resources Black Hills of Dakota, p. 335, PI. II, figs. 1-4. (Described.) 

 Lingulepis dakotensis Meek and Hayden, Whitfield, 1880, idem, pp. 337-338, PL II, figs. 10 and 11. (Copies the 



description given by Meek and Hayden, 1865, p. 2, and discusses species. Figs. 10 and 11 are copied from 



Meek and Hayden, 18G5, PL I, figs, lb and la, respectively.) 

 Lingulepis pinnaformis (Owen), Whitfield, 1882, Geology of Wisconsin, vol. 4, pp. 169-170, PL I, figs. 2 and 3. (De- 

 scribed.) 

 Lingulepis pinniformis (Owen), Dwight, 1886, Proc. Am. Assoc. Adv. Sci. for 1885, p. 208. (Mentioned.) 

 Lingulepis pinniformis (Owen), Hall and Clarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, 



figs. 237 and 238, p. 232; and PL I, figs. 16 and 17. (Mentioned. Figs. 237 and 238 are outline drawings of 



the figures given by Hall, 1863, PL VI, figs. 16 and 15, respectively; figs. 16 and 17 (PL I) are copied from Hall, 



1863, PL VI, figs. 16 and 15, respectively.) 

 Lingulepis pinniformis (Owen), Hall and Clarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, 



figs. 237 and 238, p. 548. (Mentioned. Figs. 237 and 238 are copied from those on p. 232 of the preceding 



reference.) 

 Lingulepis pinniformis (Owen), Hall and Clarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, figs. 22 



and 23, p. 60, and PL I, figs. 35 and 36. (Mentioned on pp. 60 and 61. Figs. 22 and 23 are outline drawings 



and figs. 35 and 36 are copies of the figures given by Hall, 1863, PL VI, figs. 16 and 15, respectively.) 

 Lingulepis pinniformis (Owen), Schuchert, 1897, Bull. U. S. Geol. Survey No. 87, p. 260. (Questions specific 



reference.) 

 Lingulepis pinniformis (Owen), Grabaij and Shimer, 1907, North American Index Fossils, vol. 1, p. 193, fig. 227. 



(Described. The two figures in figure 227 are copied from Hall, 1863, PL VI, figs. 15 and 16.) 

 Lingulepis prima (Hall), Grabau and Shimer, 1907, idem, p. 193. (Described, but no figures are given, and it is 



impossible to tell whether the species should be referred to Lingulella (Lingulepis) acuminata or to Lingulella 



prima.) 



General form elongate ovate, with the ventral valve subacuminate to acuminate, and the 

 dorsal valve ovate in outline. The outline of the valves varies greatly (PI. XL). On a single 

 slab of rock from Whitehall, New York, there is a range of variation that unites the slender 

 acuminate form, represented by figure Ic, with forms that are not to be differentiated from 

 Lingulella acutangula (Roemer). The range of variation in the dorsal valve is less, but it 

 varies from elongate ovate to nearly -round ovate. The convexity of the valves varies with the 

 size and condition of preservation. Those that preserve the natural convexity are rather 

 strongly convex in the dorsal valve, and about one-third less so for the associated ventral valve. 

 The variation in size is very marked, large groups of shells occurring where the average length 

 of the ventral valve is not over 6 to 10 mm. In other localities this increases to 20 mm. with 

 corresponding increase in width. 



Surface marked by concentric lines of growth, very fine concentric striae, and fine radi- 

 ating striae. When the outer layer of the shell is exfoliated, the surface is marked by flattened, 

 radiating striae and concentric lines and stride of growth. The inner surface is marked by flat- 

 tened radiating striae, and minute pits or punctae.. 



The shells from most localities are relatively thin, but some from the locality at St. 

 Croix Falls show several layers, and those from the sandstones of the Black Hills of South 



