340 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



The Kaugatoma formation is of Ludlow age, and has many faunal 

 elements in common with rocks of that division in both Scandinavia 

 and Great Britain, but with the Norwegian section the common spe- 

 cies are not so many as desirable. Species of high diagnostic value 

 which also occur in the Kristiana region of Norway in strata of Ludlow 

 age (Kiaer's stage 9) are Camarotoechia nncula, C. borealis, Chonctes 

 striatelliis, Retzia salteri, Spirifer elevatus, Grammysia cingulata, Megalo- 

 mus gothlandicus, and Cardiola inierrupta (occurs in the strata of the 

 preceding stage 8). 



In the English Ludlow the same (Megalomus gothlandicus excepted) 

 and other additional species occur, among the latter being Aviculo- 

 pecten danbyi, Cardiola inierrupta, Orthonota cymhaefonnis, Orthoceras 

 buUatum, Crotallocrinus rugosus, and also numerous eurypterids, some 

 of which are closely related to those of the Oesel formation. While 

 the identifications of some of the species named above are perhaps 

 erroneous, enough are certain to assure synchroneity. 



\Yith the North American section the Oesel formation has few spe- 

 cies in common and these are of almost universal distribution and of 

 long range. The fauna of the Eurypterus beds, however, affords a 

 most important point of faunistic contact. Schmidt first identified 

 the common eurypterid {E. fisheri) as E. remipes De Kay and later 

 both he and Holm agreed that it is little more than a geographic 

 variety of the latter.^ E. remipes is the common form of the Bertie 

 ^Yaterlime of the Salina group of New York and in addition to these 

 two forms, there are others which are closely related. If then, the 

 Sagaristi zone and the Bertie AVaterlime be considered synchronous, 

 it follows that the Kaugatoma zone finds an equivalence in 'the Coble- 

 skill, Rondout \Yaterlime, and Manlius limestones. - 



1 Schmidt. Bull. Geol. soc. Amer., 1S92, 3, p. .59. 



2 No correlation has been made with the Gotland section for the reason that the data are not 

 well enough in hand to warrant the attempt. 



