FOSSILS OF THE DEVONIAN. 157 
Formation and locality—Devonian limestone; associated with R. dupli- 
cata and R. (L.) Laura. The Gate, northwest of Eureka, Eureka District, 
Nevada. 
Rhynchonella Emmonsi H. & W. 
Rhynchonella Emmonsi Hall & Whitfield, 1877. Geol. Expl. Fortieth Par., vol. iv, p.247, 
pl. iii, figs. 4-8. 
intermedia Barris, 1878. Proc. Davenport Acad. Nat. Sei., vol. ii, p. 285, 
pl. xi, figs. 5-6. 
With the type of Rhynchonella Emmonsi before me, and a typical speci- 
men of Rhynchonella intermedia, received from Rey. W. H. Barris, to compare 
with it, I fail to observe any specific differences between them. The slight 
differences mentioned by the author of FR. intermedia would not serve to 
separate the two shells, if found in the same stratum of rock, and the range 
of variation in most species of the genus Rhynchonella is far greater than 
between the two shells under consideration. R. Emmonsi is a rare form in 
the Upper Devonian of the White Pine District, Nevada, and Rev. Mr. Barris 
writes me that it is also rarely met with in the Upper Devonian of Towa. 
There is little doubt but that Rhynchonella intermedia, R. Emmonsi, and 
R. venustula Hall are varieties of R. cuboides of the Devonian of Europe, 
and when the opportunity offers to illustrate a series of specimens I think 
this can readily be shown. _ 
Many American species now under local names will ultimately be 
placed with species described from Europe, and the reverse will also be true 
when American species have priority. Our knowledge of the widespread 
geographic distribution of paleozoic species will be greatly increased with 
better facilities for the comparison of specific forms from the great conti- 
nental areas and islands. 
Subgenus LEIORHYNCHUS Hall. 
Rhynchonella (Leiorhynchus) Nevadensis, n. sp. 
Plate xiv, figs. 9, 9a, b. 
Shell ovate or suborbicular, usually broader than long, or length and 
breadth subequal; increases in rotundity with growth. 
Ventral valve in adult individuals gibbous above, curving uniformly 
