The fauna of the Chazy limestone / by Percy E. Raymond.

  • Raymond, Percy Edward, 1879-1952.
Date:
[1905]
Catalogue details

Licence: In copyright

Credit: The fauna of the Chazy limestone / by Percy E. Raymond. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    18/32 (page 368)
    Coni pari ii^>- tlie large percentage of forniR connnon to tlie Stones Iviver and to the Black River and Trenton witli the low percentage—less than 5 per cent—of forms common to the Ohazy and Trenton, it becomes evident that the Stones River and Trenton are faunally mnch more closely connected than are the Chaz}^ and Trenton. This close relationship of the fanna of the Stones River to that of the Trenton, coupled witli the stratigi’aphy, suggests that the whole Stones River is younger than the Chazy. East Tennessee. In east Tennessee the Maclurea limestone was correlated by Salford'^ with the Chazy or Black River of New York and Canada. While a large part of this limestone seems to be of Trenton age, a section around Lenoirs has afforded the writer a small fauna containing fossils characteristic of Division 2 in the Lake Champlain region. This region needs further study before definite correlations are made. Description of New Species. BRACHIOPODA. Lingula colamba sp. nov. Shell small, oval in outline, gently and uniformly convex. There are no flat slopes and the front is semi-circular in out- line. The posterior end is somewhat triangular, the beaks pointed. The surface is covered by very numerous and promi- nent concentric striae, no radiating lines showing except when the surface is exfoliated. One specimen is long and wide; another is 7“^ long and 5““ wide. Locality.—East side of Valcour' Island at Chazy, and on Isle La Motte. Type in Yale University Museum. Camarotcechia pristhia sp. nov. Shells small, transversely oval to subcircular in outline. Both valves moderately and uniformly convex. The dorsal valve has a low fold and the ventral valve a shallow sinus, which is noticeable only toward the front of the shell. There are 10 to 14 strong i-oiinded ])lications, 4 on the dorsal fold and 3 on the sinus. Tlie 2 plications in the middle of the fold are smaller than 'the 2 outside ones and the median plication of the ventral valve is the weakest, which is the direct opposite of the state found in Camarotoeehia orientaUs. Locality.—Valcour Island and Chazy, New York. The type is in the Carnegie Museum. * Geol. Tennessee, 1869, p. 236.