166 PALEONTOLOGY OF THE EUREKA DISTRICT. 
Left valve unknown. 
Dimensions : length of shell, 4.5°™; width the same. 
This species is closely related to Pterinea Chemungensis Conrad (Pal. 
N. Y., vol. vy, pt. 1, p. 98, 1884) from the Devonian of New York. It differs 
in the more anterior position of the beak and less elongate outline. 
Formation and locality—Upper Devonian of Newark Mountain, Eureka 
District, Nevada. 
Genus ACTINOPTERIA Hall. 
Actinopteria Boydi Conrad (Sp.). 
Plate v, fig. 2. 
Avicula Boydii Conrad, 1842. Jour. Acad. Nat. Sci. Philad., vol. viii, p. 237, pl. xii, fig. 4. 
Pterinea Boydi Miller, 1877. Cat. Amer. Pal. Fossils, 2d ed., p. 201. 
Actinoptera Boydi Hall, 1883. Pal. N. Y., vol. v, pt. 1, Plates and Explanations, p. 8; 
pl. xix, figs. 2-24. 
Actinopteria Boydi Hall, 1884. Pal. N. Y., vol. v, pt. 1, p. 113. 
There is only a single left valve of this species in the collection, and 
that is somewhat distorted by pressure. A direct comparison with authentic 
specimens from the Hamilton Group of New York shows such a striking 
similarity between them and the Nevada shell that there is little hesitancy 
in identifying the species by the one specimen. 
Formation and locality—lLower Devonian of Lone Mountain, 18 miles 
northwest of Eureka, Nevada. 
Genus LEIOPTERIA Hall. 
Leiopteria Rafinesquii Hall. 
Plate v, figs. 10, 10a. 
Leiopteria Rafinesquii Hall, 1883. Pal. N. Y., vol. v, pt. 1, Plates and Explanations, pp. 
7,9; pl. xv, fig. 11; pl. xx, figs. 6,7. Ibid., 1884, text, p. 161. 
The examples of this species from Nevada embrace both the Upper 
Helderberg and Hamilton Group forms, as illustrated in the Paleontology 
of New York. The identification is made with the figures, as we have no 
typical specimens of the species for comparison. 
Formation and locality—Lower Devonian of Brush Peak and Atrypa 
Peak, Eureka District, Nevada. 
