Ps 
176 PALEONTOLOGY OF THE EUREKA DISTRICT. 
Surface nearly smooth, a few obscure lines of growth alone showing 
on the cast or matrix. 
The anterior adductor muscular scar is of medium size, and has a low 
ridge and sulcus posterior to it that start near the beak and extend nearly 
to the basal margin. 
Dimensions: height at anterior end, 1.75; near posterior end, 2°"; 
length, 11°. 
This form differs from the preceding species in its more slender form, 
the absence of a well-defined byssal furrow, and the more attenuate anterior 
extremity. 
Formation and locality—Lower Devonian of Brush Peak, Eureka Dis- 
trict, Nevada, and also at the same horizon on Lone Mountain, 18 miles 
northwest of Eureka, Nevada. 
Sanguinolites rigidus W. & W. (Sp.) 
Plate xvi, fig. 6. 
Oypricardia? rigida White & Whitfield, 1862. Proc. Boston Soe. Nat. Hist., vol. viii, 
p. 300. 
Edmondia? bicarinata Winchell, 1863. Proc. Acad. Nat. Sci. Philad., vol. xv, p. 13. 
Sanguinolites rigidi Hall, 1870. Prelim. Notice Lam. Shells, p. 44. 
rigidus Hall, 1883. Pal. N. Y., vol. v, pt. 1, Plates and Descriptions, p. 
16; pl. lxvi, figs. 1-19. 
The relative stratigraphic position of this species in the Chemung 
Group of New York and the Upper Devonian beds of The Gate, northwest 
of Eureka, is the same; and direct comparison with specimens from the 
Burlington sandstones of Iowa and the Chemung shales of New York, shows 
the two forms to be specifically identical. 
Sanguinolites ? Sanduskyensis Meek. 
Plate v, fig. 4. 
Sanguinolites? Sanduskyensis Meek, 1871. Proc. Acad. Nat. Sci. Philad., vol. xxiii, 
p. 68. Ibid., 1873. Geol. Surv. Ohio Pal., vol. i, pt. 2, p. 209, pl. xviii, fig. 3. 
Compare Modiomorpha linguiformis Hall. Pal. N. Y., vol. v, pt. 1, Plates and Descrip- 
tions, p. 12, pl. xxxiv, figs. 15-17, and M. Hyalea, p. 13, pl. xli, fig. 28. 
The external form and characters of the shell before me agree with 
those described by Mr. Meek, as shown in his figure. 
