18 
PALAEONTOLOGY OF NEW YORK. 
wrinkled into a sort of herring-bone pattern; L. distinda and L. epimia, Bar- 
rande, L. granulata, Phillips, and L. tenuigranulata, McCoy, also have very 
characteristic surface markings, consisting of granulations or tubercles with vari¬ 
ous arrangements. In the L. lamellata , Hall* from the Clinton group of central 
New York, and the commingled Clinton and Niagara fauna at Hamilton, On¬ 
tario, the surface is covered by broad, transverse, imbricating, gently undulating 
lines, which do not correspond with the curvature of the anterior margin, but 
end quite abruptly on the lateral margins. Near the umbo these lines are 
crossed by the concentric growth-lines of the shell. Of precisely the same 
character is the ornamentation in L. zebra , Barrande, from the Bohemian 
Etage E,f and closely similar to it is that of L. spathata, Hall, of the Lower 
Helderberg. 
The genus Lingula reached its culmination of development in the faunas of 
the Silurian and Devonian. In the Palseozoic of North America alone, about 
one hundred and twenty species (making allowance for synonyms and the 
necessary elimination of heterogeneous forms) are now recognized. Of these 
about seventy are from the Silurian. It is not probable that as many more 
species are known from the same formations in other countries. 
Genus LINGULOPS, Hall. 1871. 
PLATE II, FIGS. 24-29; AND PLATE IV K, FIGS. 14,15. 
1871. Lingulops, Hall. Notes on some New or Imperfectly known Forms among- the Brachiopoda, 
etc. (March). In advance of Twenty.-third Rept. N. Y. State Cab. Nat. Hist. 
1872. Lingulops, Hall. Idem. (March). Reprinted with Explanations of Figures. 
' 1873. Lingulops, Hall. Idem. Twenty-third Rept. N. Y. State Cab. Nat. Hist., p. 245. 
1874. Lingulops, Davidson and King. Quart. Journ. Geol. Soc., voh xxx, p: 164. 
1875. Lingula, U. P. Jambs. Cincinnati Quart. Journ. Sci., vol. ii. 
Of this remarkable and interesting genus but three representatives are 
known. Two of these are from faunas probably equivalent, but from widely 
distant localities; Lingulops Whilfieldi , the type-species, from a chocolate-brown 
* This name has been applied to two distinct species, one from the Clinton group (Pal. N. Y., vol. ii, 
p. 55, pi. xx, figs. 4 a, b, c), the other from the Niagara shales at Lockport and elsewhere (Geol. Rept. Fourth 
Dist. N. Y., 1843, p. 109, fig. 2; Pal. N. Y., vol. ii, 1847','p. 249, pi. liii, figs. 1 and 2). .The latter has 
priority, and the former, that above mentioned, may receive the designation, Lingula taniola. 
t Syst. Sil., vol. v, pi. 105, fig. Zy. 
