NIAGARAN (aNTICOSTIAn) SERIES 709 



lent sections may be obtained at the type locality where Gun River flows 

 across the strata. 



On the north shore this formation may be seen from Wreck Beach to 

 East Cliff, where excellent sections are obtainable. Here considerable 

 shale is present in the lower part of the formation and a fauna different 

 from the equivalent beds of the south shore. The higher strata are more 

 calcareous and have more coral reefs than those of the south shore. 



The detail of the various beds is as follows : 



Hyattella congesta teds. p^^^ 

 D5 (=D2-D3). South shore. Ash gray to yellowish white thin-bedded 

 limestones abounding in corals and intraformational con- 

 glomerates 70 



These zones may be seen to best advantage at Saint Marys, 

 Saint Anns, and in the lower portion of Hannah Cliff. The 

 more common fossils are 8tromatopora, Favosites gothlandicus, 

 F. venustus, Halysites catenulatus, and Conchidium. 



Dg (=D4). South shore. Pinkish gray limestones with thin shale 



partings and local coral reefs 60 



These beds may be seen at the top of Hannah Cliff and east- 

 ward to 3 miles west of Gun River. Of fossils there are 

 Stromatopora, Favosites gothlandicus, F. venustus, Heliolites 

 afflnis, H. exiguus, Zaphrentis (?) pygmwa (very small, in 

 greatest profusion), Bhipidomella cf. circula, Rafinesquina pro- 

 funda (very common), Rhynchonella Mdens (abundant), R. cf. 

 glacialis (common), Hyattella congesta (first appearance at 

 base of this zone in small specimens), Whitfieldella (small), 

 Platyceras cf. niagarense, Calymene cf, vogdesi (large), and 

 an abundance of small ostracoda. 



De- North shore. On the west side of Fox Bay and on the east side at 

 Reef Point this zone is to be seen. At Reef Point Heliolites 

 exiguus is extremely common. At the other place were collected 

 Orthis flahellites, Schuchertella pecten, and Hyattella congesta. 



D7 (^Dg-De). South shore. Same character of strata as before. 

 Seen about Gun River and to the west and to the east of this 



river for 2 miles 113 



Same corals as before. Pasceolus, Semicoscvnium, Phwno- 

 pora expansa, Helopora fragilis, Pholidops ovata (exceedingly 

 abundant) , Orthis flal)ellites, Rafinesquina profunda, Schuchert- 

 ella pecten, Rhynchonella hi dens, Hyattella congesta, Leper- 

 ditia (large), and Illwnus. 



Dj. North shore. These zones of the south shore are here developed 

 under different physical conditions and have a resulting differ- 

 ent faunal assemblage. On the south shore the habitat was 

 one of limestone, while on the north shore the environment was 



XLIX — Bull. Geol. Soc. Am., Vol. 21, 1909 



