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Show 354 These Sucia and Koinooks beds are also almost certainly representatives of those of the New Jersey Qreensand series, containing Ammonites complexus, Placenticeras placenta, Nautilus Dekagi, Baculites ovatu*} Oryphcea vesicularis, Inoceramus Barabini, & c, as well as of the Upper Chalk of Europe. 4 SMITHSONIAN INSTITUTION, Washington City, June, 1871. CARBONIFEROUS SPECIES. BRACHIOPODA. Genus PRODUCTUS, Sowerby. PRODUCTUS LATISSIMUS, Sowerby. Pkte 1, fig. 1. Prodxctus latmimvB, Sowerby ( 1822), Mineral Conch., pL 330.- Phillips ( 1836\ G* © 1. York8., ii, pi. viii, fig. 1.- DeKoninck ( 1847), Monogr Chonetes et Prod., pi. ii, fig. 2; and pi. iii, fig. 2.- Davidson ( 1861), Scottish Carb. Brach., pi. ii, figs. 8, 9; and ( 1657), Monogr. British Carb. Brach., 145, pi. xxv, figs. 1- 4. Shell attaining a large size, thin, rather depressed, much wider than long, with a subsemicircular outline; anterior margin not produced; hinge- line long, straight, but apparently not qtiite equaling the greatest breadth. Ventral valve moderately convex or arched, with a regularly-increasing curve from the front to the beak; anterior margin not produced and presenting a more or less nearly semicircular outline; beak incurved, but not prominent; lateral extremities slightly rounded; ears more or less arched, and not in any way defined from the convexity of the central region, which is nearly or quite without a mesial sinus; sea* of divaricator muscles distinct and subquadrate; surface without concentric wrinkles, and marked by moderately distinct, rounded, rather small, radiating costae, or coarse striae, that generally increase by intercalation, and number about four or five in the space of 0.20 inch, near the front. Dorsal valve unknown. Length, 1.67 inches; breadth, about 2.53 inches; convexity, 0.71 inch. Although I have seen only very imperfectly- preserved specimens of this shell, they agree so nearly in almost all of their known characters with P. Utissimus of Sowerby that 1 can scarcely doubt their identity with that species, which has not, I believe, before been even provisionally identified from any American locality. None of our specimens show the little short spines seen on the ventral valve of Sowerby's species, but they are all more or less worn, while some slight remains of what appear to be the bases of a few of these spines are seen on some of the specimens. At first I was rather inclined to think this shell might belong to tbe closely- allied P. giganteus of Martin; but the fact that well- preserved internal casts of the ventral valve show no traces of the cavities for the reception of the internal spiral arms, such as occur in P. gigantm, favors the conclusion that it more probably belongs to P. latissimu*. It also agrees with the latter, and differs from the former, in having its ears passing gradually into the convex part of the shell without any depressions to mark the limits between these parts. This latter character, and the lateral extension of the ears, however, are better seen in |