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Seite 188 - Alabama eocene, and find that, except in the extreme quadrate forms, 1 they are absolutely identical in all characters save one. The hinges are so similar that I despair of making an intelligible written description of their minute differences, and should hardly feel willing to trust an artist with their delineation.
Seite xiv - The Shasta Group is a provisional name, proposed to include a series of beds of different ages, but which, from our imperfect knowledge of the subject, cannot yet be separated; it includes all below the Chico Group. It contains fossils, seemingly representing ages from the Gault to the Neocomien, inclusive, and is found principally in the mountains west and northwest of the Sacramento Valley.
Seite xiii - It was also discovered, by the different members of the Survey, at various points on the eastern face of the same range, as far south as New Idria, and, in the summer of 1866, by Mr. Gabb, in Mendocino county near Round Valley, the latter locality being the most northern point at which it is yet known.
Seite 184 - Griswold's, southeast of the Sheep Well, on the road from San Juan to New Idria.
Seite xiv - Neocomien, inclusive, and is found principally in the mountains west and northwest of the Sacramento Valley. Two or three of its characteristic fossils have been found in the vicinity of Monte Diablo, and one of the same species has been sent from Washington Territory, east of Puget Sound.
Seite 53 - ... very obliquely subtruncate above, produced and rounded below; posterior end broadly and regularly rounded, a little less prominent below than above the middle ; basal margin nearly straight. Surface nearly smooth in the middle, marked by pretty distinct lines of growth towards the ends, especially above. Length from beak to base, 1.3 inch ; width, 2.6 inch ; beak to anterior end, 1.45 inch.
Seite xiii - Dickerson, RE, Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, pp. 171-7, 1911. 11 Cooper, JG, Cal. Acad. Sci.. vol. 5, 1873, pp. 419-422. California. "The Tejon is found most extensively developed in the vicinity of Fort Tejon and about Martinez. From the latter locality it forms an almost continuous belt in the Coast Ranges to Marsh's, 15 miles east of Mt. Diablo, where it sinks under the San Joaquin plain. It...
Seite 196 - Shell small, trigonal, elongate; beaks prominent, anterior; cardinal margin sloping posteriorly; straight to slightly convex or concave; anterior end regularly rounded ; base broadly rounded, most prominent in the middle ; posterior end narrowly truncated. Surface marked by regular, square, concentric ribs, with equal, flat, interspaces; these ribs end abruptly in advance, and are continued by fine lines starting with an angle somewhat less than a right angle; posteriorly there is an angular ridge...
Seite 24 - This species was described by Gabb as follows : Shell broad, inequilateral; beaks in advance of the middle; cardinal margin nearly straight and sloping; anterior end very much produced, rounded and narrow; posterior end obliquely truncated; base broadly and regularly rounded. Surface marked by numerous Irregular and rather strong lines of growth. The hinge plate of this species is wide, the chondophore oblique, shallow, very slightly overhung by the posterior arm of the cardinal; left cardinal heavy,...
Seite 32 - Shell equivalve, subcircular, broader than long, convex ; beaks small ; sides sloping concavely above, rounded below; ears small, subequal, roughened and irregular, sinus very small. Surface marked by eighteen or twenty flat ribs, with flat or slightly concave interspaces; margins undulated, the ends of the ribs being deeply emarginated, and the interspaces being prolonged into tongue-like processes.