The Canadian and Ordovician Formations and Fossils of South ManchuriaU.S. Government Printing Office, 1932 - 152 páginas An attempt is made in this monograph to bring inot systematic order the facts that have thus far been ascertained regarding the Canadian and Ordovician strata of South Manchuria. Part 1 deals with he stratigraphy, containing descriptions of the formations and sections as they occur at various localities; Part 2 is biologic in scope, comprising mainly descriptions of the new material found by the author as well as an attempt to present a complete critical review of previous studies. Holotype specimens listed contain United States National Museum catalog numbers. |
Otras ediciones - Ver todas
The Canadian and Ordovician Formations and Fossils of South Manchuria Riuji Endo Vista completa - 1932 |
The Canadian and Ordovician Formations and Fossils of South Manchuria Riuji Endo Vista completa - 1932 |
Términos y frases comunes
Actinoceras Aigawa annulations apical angle Armenoceras Berkeley black banded limestone black lime brachial valve calcareous matrix camerae occupy Cameroceras Canadian cephalon China concavity conch connecting rings convex cross section Cryptolithus Cycloceras diverticula dolomitic dorsal enlarging fauna FIGURE Formation and locality Formation and locality.-Lower Formation and locality.-Middle gastropods Genus Grabau holotype Hsiao-shih Huang-pa-yi inner margin interior Kangyao formation Kobayashi lateral diameter lateral direction length equal Liao-tung locality.-Lower Ordovician locality.-Middle Ordovician Lophospira Lower fossil horizon Middle Ordovician miles south Moderately thick-bedded Niu-hsin-tai colliery north of Pen-hsi-hu number of camerae occupy a length Ordovician strata Ormoceras Orthoceras pedicle valve Pen-hsi-hu colliery Plectoceras polished vertical section pygidium Sactoceras Santao formation segments septa septal necks septum shell Shensi showing the structure siphuncle slightly slope South Manchuria South Manchuria Railway species PLATE species undetermined PLATE species_ Ssuyen formation umbilicus UNIVERSITY OF CALIFORNIA upper ventral wall whorls width Wu-hu-tsui Wuting formation Yen-tai colliery
Pasajes populares
Página 93 - ... Soc. London, 2d Ser., 5, 1840, p. 709. Type specimen. — Conch estimated to be approximately 36 mm. in diameter. Siphuncle subcentral in position. Four segments of the siphuncle occupy a combined length of 37 mm., averaging slightly more than 9 mm. for the length of a single segment. Apparently four camerae occupy a length equal to the diameter of the conch. The septa are deeply concave; their concavity equals the length of about one and a half segments of the siphuncle. The diameter of these...
Página 68 - ... longitudinal striations which show no tendency toward disappearance in adolescent or adult stages. In a specimen 85 mm. long, diameter at the smaller end 12 mm., and at the larger 19 mm., indicating an apical angle of nearly 5 degrees. 222 In this length there are nineteen annulations, or five annulations in a length equal to the diameter of the conch. Where the diameter is 15 mm., the more prominent, or primary, vertical striae usually are between 1-8 and 2 mm. apart. Midway between the primary...
Página 77 - ... but they list it as a distinct species. In view of the above, the writer has thought it best to refer his specimens to a new species and to call attention to the similarity. The distinguishing characters of this species are the slight adoral expansion of the conch, the large marginal siphuncle, and the number of camerae in a length equal to the lateral diameter of the phragmacone. By means of these characters the species is easily distinguished from all other endoceratoids, with the possible...
Página 60 - In the cross section of the siphuncle near the top three endocones are found, laid in rows dorsoventrally; 4.5 camerae occupy a length equal to the lateral diameter of the conch. Where...
Página 101 - At mid-length three camerae have a total length of 44 mm., indicating about 3-5 camerae in a length equal to the lateral diameter of the conch. The sutures of the septa are distorted by pressure, but appear to have been directly transverse originally.
Página 95 - ... equal to the dorso-ventral diameter at the top of the series counted. The camerae above this level are not exposed, so that it is not possible to determine the total length of the phragmacone. The siphuncle is located close to the ventral wall of the conch. In its present condition it is 2 mm. distant from the ventral wall of the conch where the dorso-ventral diameter of the latter is 28 mm...