702 SCHUCHERT AND TWENHOFEL ORDOVICIC-SILURIC SECTION 



Hormotoma gigantea l)eds. P^^^ 



Cg. Gray to greenish nodular limestone with greenish shale. Last 

 occurrence of Beatricea. Seen on the east and west sides of 

 Ellis Bay, Point Laframboise, and Prinstie Bay of north shore. 12 



First marked coral reef 'beds. 



Cio. Thin-bedded gray limestones abounding in Schuchertella pecten . . 10 

 Cii. Coral reef limestone. Corals in domes up to 3 feet high. Seen at 



Point Laframboise, Capes Henry and Eagle 10 



Zones Ci to Cg. Junction Cliff or Dinorthis porcata beds. The lower 

 20 feet of this zone abound in Dinorthis porcata, with which are asso- 

 ciated PlatystropJiia hiforata (as in Qq), OrtJiis laurentina (rare, first 

 appearance), Clitamhonites diversus, Leptcena rhomhoidalis (first appear- 

 ance), Hindella umhonata (rare, first appearance), Atrypa marginalis 

 (first appearance and rare), Byssonychia siihrecta, Columnaria halli, and 

 Protaroea vetusta (Eichmondian form). 



From the higher beds, or the upper 40 feet, there are the same brachio- 

 pods, but here D. porcata is rare and 0. laurentina is common. Atrypa 

 marginalis is also more common, and at the very top becomes the most 

 abundant fossil, a few beds of Cg being found composed almost wholly of 

 this form. 



^Zone Cg. Ellis Bay or Parastrophia reversa beds. This horizon in the 

 shale beds is profuse in good fossils, of which the following are the more 

 diagnostic forms : Hindia sphceroidalis, Pasceolus, Stromatopora, Favo- 

 sites ( ?) gothlandicus, Heliolites (?) speciosus, H. (?) exiguus, Lingula 

 quadrata, Platystrophia hiforata, P. cf. reversata (both species are of the 

 European stock, with odd number of plications on the fold), Orthis fla- 

 hellites, 0. laurentina, Dinorthis porcata (rare), Hehertella maria, Lep- 

 tcena i-homboidalis, Rafinesquina imbrex, Strophomena fluctuosa, Schu- 

 cherteUa pecten (first time), Clitambonites diversus, Parastrophia reversa 

 (in profusion), Rhy7ichonella (?) janea, Atrypa marginalis, Hindella 

 umhonata (greatest abundance), Byssonychia subrecta, B. superba, Con- 

 radella pannosa, BilUngsites canadensis, etcetera. 



Zone Cj. Ellis Bay. The fauna has Pasceolus, Beatricea undulata, 

 Orthis laurentina (very common), Hehertella maria, Clitambonites di- 

 versus, Leptcena rhomhoidalis, Schuchertella pecten, At7^ypa marginalis. 

 Hindella umhonata (small), and Isotelus of susce type. At the top of 

 this zone occur the additional forms Platystrophia cf. reversata, P. bifo- 

 7'ata (small), Phylloporina, Encrinurus, and Cyphaspis cf. girardeau- 

 ensis. 



Zone Cs- Korth shore. On the northeast shore at Table Mountain, West 

 Brook of Prinstie Bav, and in the lowest sandstone with nodular shale 



