8 PROCEEDINGS OF THE NATIONAL MUSEUM vol. TO 



Blancliester division — Continued. 



Coral bed (W. 15). Rather barren blue clay witli a few even-bedded 

 limestone layers showing fossils upon their surface. Calapoecia crihri- 

 formis, Columnaria alveolata, C. vacua, and Tetradium occur in the clay, 

 while Plectorthis (Austinella) scovillei is found only in a thin limestone 

 bed in the middle of the division 8' 



Upper disturbed layers (W. 14). Two layers, each about 6 inches thick, 

 of disturbed material, chiefly shells of Rafinesquina alternata standing 

 on edge. These two beds are separated by a foot of undisturbed shale 

 and limestone. Rhynchotrema dcntatum rare in the lower disturbed bed, 

 its only occurrence in the Richmond of this area 2' 



Homotrypa daicsoni beds (W. 13). Compact blue clay, bearing an occa- 

 sional thin limestone layer, with Homotrypa dawsoni, the most common 

 fossil. Mastiffograptus graclllimus and Ateleocystites lalanoide? also 

 present 3' 



Strophomena nutans bed (W. 12). Thin shelly limestone crowded with 

 SStrophomend nutans and S. ncglecta, also with specimens of S. planum- 

 Jjona elongata 4^5' 



Platystrophia annieana bed (W. 11). Even-bedded layers of limestone 

 and shale with Platystrophia annieana, Rcteocrinus nealli, and Strepte- 

 lasma dispandum appearing for the first time 3' 



Lower disturbed layer (W. 10). Shaly limestone layers 6 inches thick 

 filled with valves of Rafinesquina alternata standing on end, underlaid 

 by one foot of clay and thin limestone with few fossils 1. 5' 



Isotelus gigaa bed (W. 9). Compact blue clay abounding in well-preserved 

 fossils, particularly pelecypods {Opisthoptera, Psiloconcha, Cuneamya, 

 etc.), and containing entire specimens of /. gigas more abundantly than 

 at any other horizon 3' 



Basal beds (W. 8). Claystone and shale with many long ranged species. 

 Dalmanella meeki, Plectambonites rugosus clarksvillensis, and Zygospira 



tnodesta noted 7' 



Clarksville division (Beds W. 5-7) : 



Lower Hebertella insculpta bed (W. 7). Bhie limestone and shale like 

 that at base (W. 5) but containing Hebertella insculpta, Protarea rich- 

 mondcnsis and Pterinea corrugata, Catazyga headi schuchertana, 

 Dinorthis carleyi-insolens, etc. A heavy compact argillaceous layer up 

 to 7 inches thick forms the capstone to this bed with Dalmanella meeki 

 in abundance 3' 



Middle beds (W. 6). Lumpj', dark blue, iiibbly limestone mingled with 

 granular, dark blue clay containing broken and waterworn shell frag- 

 ments, particularly Dalmanella meeki and holding many minute fossils 

 (Cyclora, etc.) 9' 



Plectambonites clarksvillensis bed (W. 5). Rather even bedded blue lime- 

 stone and shale with first appearance of Streptelasma rusticum, Plec- 

 tambonites rugosus clarksvillensis, Rhynchotrema capax, Strophomena 



sulcata, 8. plammibona, and crowded with Dalmanella meeki 3' 



Fort Ancient division (Beds W. 1-4) : 



Orthoceras fosteri bed (W. 4). Soft, dove colored clay with many fossils 

 especially Orthoceras fosteri, Calymene meeki, Paleschara beam, Cypho- 

 trypa clarksvillensis, Suecoceras inequabile, Columnaria alveolata, Te- 

 tradium, Stromal ocerium ohiocnsis, Spatiopora tuberculata, etc 5' 



