36 PALEONTOLOGY. 



with the shell mostly exfoliated, this form seems to agree well with the 

 above-cited New York species, as may be seen by comparing our figure with 

 fig. 2, pi. 9, of the 4th vol. N. Y. Palaeontology. It is quite possible, how- 

 ever, that a direct comparison with New York specimens might show it to 

 be distinct. I do not feel justifiable, however, without a good series of 

 specimens from the two distantly-separated localities for comparison, in run- 

 ning the risk of further complicating the synonymy of a species that has 

 already received so many names, and consequently prefer to refer it to the 

 New York species, instead of attempting to name it as new. 



Locality and position. — Colonel Simpson's collection, latitude 39'^ 30' 

 N., longitude 115° 36' W.; from dark Devonian limestone. 



PRODUOTID^. 



Genus PRODUCTUS, Sowerby. 

 Peoductus subaculeatus, Murchison ■? . 



Plate 3, figs. 7, 7 a, 7 6. 



Productm subaculeatus, Murchison (1840), Bull. Soc. Geol. Pr., XI, 255, pi. ii, fig. 9. — 

 De Verneuil (iu part) (1845), Geol. Euss. and the Ural Mts., 11,282, pi. xvi, 

 fig. 9.— De Koninck (1847), Mem. Soc. Eoy. Li6ge, IV, 249, pi. xiv, fig, 4; and 

 Monogr. Prod, aud Ghon., 142, pi. xvi, fig. 4.— De Vera. (1847), Bull.— Soc. 

 Geol. Fr., 2d ser., IV, 705, pi. Ix.— Schuurr (1853), in Dunker and von 

 Meyer's Paleeout., II, 228, pi. xliii, fig. 4 a. — Davidson (1853), Quart. Jour. 

 Geol. Soc, 336, pi. xv, fig. 12. — Sandberger (1855), Die Brach. Eeiniscb. 

 Schicht. Nassau, 75, pi. xxxiv, fig. 17. — Davidson (1865), Monogr. Brit. Devon. 

 Foss., 99, pi. XX, parts 1-2. — Meek (1876), Col. Simpson's Eeport Expl. across 

 the Great Basin of Utah, 345, pi. i, figs. 3 a, 6, c. 



Leptcena fragaria, Sowerby (1840), Trans. Geol. Soc. Loud., 2 ser., V, 704, pi. Ivi. fig. 

 5.— Phillips (1841), Pal. Foss., 59, pL xxv, fig. 100. 



Leptcena (Strophalosia) subaculeata, McCoy (1852), Brit. Pal. Foss., 388. 



Comp. P. Sliumardianus var. pyxidatus, Hall (1858), Iowa Eeport, I, part 2,498 and 

 499. 



Shell small, thin, truncato-subhemispherical ; hinge equaling or less 

 than the greatest breadth ; ears small, nearly rectangular, or somewhat 

 rounded ; lateral margins rounding to the front, which is regularly rounded 

 in outline. Ventral valve moderately convex, the greatest convexity being 

 near the middle, without any traces of a mesial sinus ; beak not very prom- 

 inent, incurved, though without distinctly passing within the hinge-margin; 



