Contributions to the Cretaceous Paleontology of the Pacific Coast Volume 133; The Fauna of the Knoxville Beds (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Length, 5 mm.; height, 3 mm. The generic position of this little species is somewhat doubtful, as it is known only from the type specimen, which is a cast of a left valve broken at the posterior end. Its form and surface sculpture, however, are sufficiently characteristic to make it easily recognizable. Locality and position.?From the small limestone, 3 miles northwest of Paskenta, Cai., and about 3,000 feet below the top of the Knoxville beds. (National Museum Catalogue, Mesozoic Invertebrate Fossils, 23061.) CORBULA PILOSA ?. Sp. PI. XI, figs. 1 and 2. Shell small, oval, convex; beaks rather prominent, a little in advance of the middle; cardinal margin sloping almost equally from the beaks in front and behind; anterior end regularly rounded arid narrower than the posterior end, which is also rounded, but more prominent above than below; ventral margin forming a broad curve; surface marked by slender filiform concentric lines, with somewhat broader interspaces. Some examples show an ill-defined subangular umboual ridge extending from the beaks to the postero-basal margin. Length of a large specimen, 19 mm.; height, 13 mm.; convexity of single valve, about 7 mm. A provisional name is given to this form because it can not be referred to any of the described species from related deposits on the Pacific Coast. Corbula concinna Whiteaves (Mesozoic Fossils, Yoi. I, p. 219, pi. 29, figs. 3, ), from the Queen Charlotte formation, is similar in some respects, but it differs essentially in outline, especially of the posterior portion, besides being a smaller form. Locality and position.?In the upper part of the Knoxville beds, on Cold fork of Cottouwood Creek, near Stepheuson's, Tehama County, Cai. lepresented by twelve specimens. (National Museum Catalogue...