196 
PALEONTOLOGY OF NEW YORK. 
(2) 1878. 
(3) 1878. 
(4) 1878. 
(2) 1879. 
(2) 1883. 
(1) 1883. 
(2) 1884. 
(4) 1884. 
(3) 1884. 
(4) 1884. 
(4) 1890. 
(4) 1891. 
Uncinulus, Ba'xle. Explic. de la Carte geolog. France, vol. iv, Atlas, pi. xi, figs. 17-20. 
Uncimilina, Baylb. Explic. de la Carte geolog. France, vol. iv. Atlas, pi. xiii, figs. 13-16. 
Rhynchonella, Barkis. Proc. Davenport Acad. Nat. Sci., vol. ii, p. 285, pi. xi, figs. 5, 6. 
Rhyndionella, Hall. Twenty-eighth Ann. Kept. N. Y. State Mus. Nat. Hist., p. 165, pi. xxvi, 
figs. 34-40. 
Uncinulus, Waagen. Salt-Range Fossils, Brachiopoda, p. 424. 
Rhynchonella, Davidson. Brit. Silur. Brachiopoda; Suppl., p. 156. 
Uncinulus, QUhleet. Bull, de la Soc. g6ol. de France, 3d ser., vol. xii, pp. 426-432, pi. xxi, 
figs, la-s; jil. xxii, figs. 2 a-n. 
Rhynchonella, Walcott. Monogr. U. S. Geol. Surv., vol. viii, p. 157. 
Rhynchonella, CEhlert. Bull, de la Soc. geol. de France, 3d ser., vol. xii, p. 420, pi. xviii, 
fig. 5a-o. 
Rhynchonella, Clarke. Neues Jahrb. fiir Mineral., Beilagebnd. iii, p. 385. 
Rhynchonella, Williams. Bull. Geol. Soc. America, vol. i, pp. 481-500, pis. xi, xiii. 
Rhynchonella, Clarke. American Geologist, August, p. 100. 
There are large numbers of palteozoic rhynchonellas which are characterized 
by a full subcuboidal or subpentahedral contour, a fold and sinus not sharply 
developed except at the anterior margin, an abrupt anterior slope, sharply ser¬ 
rated lateral margins of contact, and low surface plications, each of which, on 
the front of both valves, is marked by a fine median line. 
Shells with such external features appeared in the middle or upper Silurian, 
multiplied in the early Devonian, and continued their existence into the faunas 
of the Carboniferous, They were early distinguished as the group of Rhyncho¬ 
nella Wilsoni, Sowerby, taking their name from the common species of the 
Wenlock fauna, which was quite fully described and illustrated by Davidson in 
the Annals and Magazine of Natural History, 1852,* * * § and still more elaborately 
in his Silurian Brachiopoda, 1869.f In 1871, Quenstedt^ termed the shells 
“ die Wilsonier ” or “ the Wilsoni’s,” introducing for them a trinomial nomen¬ 
clature, as, for example, R. Wilsoni Bohemica, R. Wilsonipila, etc., etc. 
That this term was not intended as a generic or subgeneric designation is 
evident from its mode of use, but in the same year Professor E. Kayser, § in 
referring to Quenstedt’s recently expressed opinion, says that “ the characters 
[mentioned] seemed to him [Quenstedt] sufiicient for the establishment of 
a separate subgenus “ Wilsonia.” Thus the name Wilsonia was introduced, 
* P. 249, pi. xiii, figs. 12-14. 
t P. 168, 111. xxiii, figs. 1-18. 
J Petrefactenkunde Deutscblands ; Brachiopoden, p. 193. 
§ Zeitschrift dei‘ deutsch. geolog. Gesellsch., vol. xxiii, p. 502. 
