UN.] 



BRA CHIOPODA. 



349 



alveata, Hall, 1863, 16th Rep. N. Y. St. 



Mus. Nat. Hist., p. 23, and Pal. N. Y., 



vol. 4, p. 12, Ham. Gr. 

 ampla, Owen, 1852, Geo. Sur. Wis., Iowa, 



and Minn., p. 583, Potsdam Gr. 

 antiqua, Emmons, 1842, Geo. Rep. N. Y., 



p. 268, and Pal. N. Y., vol. 1, p. 3, Pots- 

 dam Gr. 

 antiquata, Emmons, 1856, Am. Geol., p. 



202, Potsdam Gr. 

 artemis, Billings, 1874, Pal. Foss., vol. 2, 



p. 14, passage beds between Up. Sil. 



and Devonian. 



hemispherica, Sowerby, 1839, (Atrypa | 

 hemispherica,) Murch. Sil. Syst., p. 639, j 

 and Pal. N. Y., vol. 2, p". 74, Clin- 

 ton Gr. 



imbricata, see Trematospira imbricata. 



intermedia, Hall, 1860, Can. Nat, and Geo., \ 

 vol. 5, p. 144, Up. Sil. 



planoconvexa, Hall, 1852, (Atrypa piano- j 

 convexa,) Pal. N. Y., vol. 2, p. 75, Clin- | 

 ton Gr. 



propria, Hall, syn. for L. flabellites. 

 LINGULA, Bruguiere, 1792, Encyc. Meth., j 

 tab. 250. [Ety. lingula, a little tongue.] j 

 Shell oblong or ovoid, 

 depressed, thin, gaping 

 at each end, rounded or 

 subtruncate in front, 

 pointed at the beaks, 

 consisting of alternate 

 fibrous, corneous, and tu- 

 bular testaceous, phos- 

 phatic laminae ; valves 

 convex, held together by 

 the action of muscles, 

 beak of ventral valve 

 more pointed and promi- 

 nent than the other; 

 surface smooth or con- 

 centrically lined ; pe- 

 duncle long, thick, cylin- 

 drical, fleshy, and flexible; 



there are twelve muscular FIG. 573. Lingula anatina. o, Anterior adductors; a, posterior 

 impressions in the dorsal adductor : pp, external protractors; pp, central protractors; rr, 

 anrl tViirtA^n in tVio anterior retractors; r, posterior retractors; c, capsule of pedicel; 

 ana tnirteen m tne n , visceral sheath ; o, (esophagus ; .v, stomach ; J, liver; v, vent; 

 ventral, valve. Type L. h, auricles, etc. 

 anatina. No Palaeozoic 

 shell is positively known to agree with 

 this genus in its muscular impressions, 

 and probably none belong to it. Many 

 referred to it belong to Lingulella, 

 others to Lingulepis, and others, may 

 be, to undefined genera. The external 

 appearance, however, resembles Lin- 

 gula, and for want of material to distin- 

 guish internal characters, they are left, 

 provisionall} r , where the authors of the 

 species left them. 



acuminata, Conrad, 1839, Ann. Rep. N. Y., 

 Calcif. Gr. 



FIG. 572. Lingula acuminata. 

 a, b, c, and e are ventral valve 

 /and g are young shells. 



Various forms; 

 ; d, dorsal ; and 



acutangula, Roemer, 1852, Kreid. von 



Texas, p. 90, Silurian, 

 acutirostra, Hall, 1843, Geo. Rep. 4th Dist, 



N. Y., p. 77, and Pal. N. Y., vol. 2, p. 



56, Clinton Gr. 

 jequalis, Hall, 1847, Pal. N. Y., vol. 1, p. 



95, Trenton Gr. 

 albapinensis, Walcott, 1885, Monogr. U. S. 



Geo. Sur., vol. 8, p. 108, Devonian. 



attenuata, Sowerby. The fossil referred 



by Hall to this species is described by 



Billings under the name of L. daphne. 

 aurora, see Lingulella aurora, 

 belli, Billings, 1859, Can. Nat. Geo., vol. 4, 



p. 431, Chazy Gr. 

 bicarinata, Ringueberg, 1884, Proc. Acad. 



Nat. Sci., p. 149, Niagara Gr. Not de- 

 fined so as to be recognized, 

 billingsana, Whiteaves, 1878, Am. Jour. 



Sci. and Arts, 3d ser., vol. 16, p. 226, St. 



John's Gr. 

 bisulcata, Ulrich, 1889, Am. Geol., vol. 3, 



p. 380, Utica Slate, 

 briseis, Billings, 1862, Pal. Foss., vol. 1, p. 



48, Trenton Gr. 

 calumet, N. H. Winchell, 1885, 13th Ann. 



Rep. Geo. Sur. Minn., p. 65, Taconic. 



Probably an Obolella. 

 canadensis, Billings, 1862, Pal. Foss., vol. 



1, p. 114, Hud. Riv. Gr. 

 carbonaria, Shumard, 1858, Trans. St. 



Louis Acad. Sci., vol. 1, p. 215, CoalMeas. 

 centrilineata, Hall, 1859, Pal. N. Y., vol. 



3, p. 155, Low. Held. Gr. 

 ceryx, Hall, 1863, 16th Rep. N. Y. St. Mus. 



Nat. Hist,, p. 19, and Pal. N. Y., vol. 4, 



p. 5, Schoharie grit, 

 clintoni, Vanuxem, 1842, Geo. Rep. N.Y., 



p. 79, and Pal. N. Y., vol. 2, p. 54, Clin- 

 ton Gr. 

 cobourgensis, Billings, 1862, Pal. Foss., 



vol. 1, p. 50, Trenton Gr. 



