NIAGARAN (aNTICOSTIAn) SERIES 715 



In this correlation there are seen certain peculiar and divergent faunal 

 elements. For instance^ in the Williamson division of the New York 

 Clinton, HyattelJa congesta characterizes this zone, but on Anticosti this 

 species is at home during an earlier time in the lower Gun Eiver forma- 

 tion, and it is not known at all in the Jupiter Eiver deposits. Coral reefs 

 in the Mississippian sea are not prominent until long after the introduc- 

 tion of the Niagaran, but on Anticosti the coral reefs dominate all Anti- 

 costian time. Pentamerus oblong us appears in the Gun Eiver deposits 

 long before it is seen in New York. Anoplotheca hemispherica appears 

 near the top of the Gun Eiver deposits, and thence continues to the very 

 top of the Jupiter Eiver, thus ranging through 650 feet of calcareous 

 deposits. 



Chicotte formation {Richardson's Division F). — This series of lime- 

 stones is strikingly different from any of the preceding in that they are 

 more heavily bedded, have almost no shale partings, and are white and 

 coarsely granular^ due to the crinoidal pieces, corals, and Stromatopora 

 of which they are mainly composed. The contact with the Jupiter Eiver 

 formation is abrupt and there appear to be no transition beds between 

 them. The total thickness is about 70 feet. 



These limestones are well displayed at Southwest Point, where they are 

 decidedly undulatory, and recur at intervals eastward to Pavilion Eiver. 

 The most continuous section was seen at the type locality for the forma- 

 tion in the cliffs westward from Chicotte Eiver, where the beds are more 

 undulatory than elsewhere. The zones are as follows : 



Feet 

 Fi and Fo. Gray slightly granular limestone with green shale partings. IS 

 Seen at the Jumpers and Chicotte Cliff. At the eastern end 

 of the section these zones include Stromatopora reefs. Corals 

 are common as Stromatopora, Favosltes favosus, F. gothlandi- 

 ciis, F. venustus, Alveolites lahechi, HeUoUtes exiguus, Ptycho- 

 phyllum canadense, and Ormoceras canadense (Huronia verte- 

 'bralis). 

 F3 and F4. White granular crinoidal limestone in beds from 6 to 18 



inches and without shale partings 55 



Has F. favosus, Orthis flahelUtes, Leptwna rhomhoidaUs, 

 Atrypa reticularis, Gyrtia myrtea, Spirifer radiatiis, Pliragmo- 

 ceras (small). Very large crinoid stems occur, possibly of 

 Crotalocrinus. 



Correlation. — The fauna of the Chicotte formation is as yet a small 

 one and there is little on which to base positive correlations. Most of the 

 species are those of the lower horizons, while the new elements in the 

 crinoidal life are so comminuted that nothing can be made of it. It 



