R. S. Lull — Life of the Connecticut Trias. 399 



Triassic trough is about 110 miles, from the village of Northfield, 

 Massachusetts, on the north, to New Haven bay on the south. 

 Its width varies, but averages some 18 miles, the total area 

 being not far from 2000 square miles. 



This Triassic depression is bounded on either side by eleva- 

 tions of the more ancient crystalline rock, none younger than 

 the Paleozoic, the weathering of which constituted the source 

 of the Triassic sediments. The age of the latter, which has 

 been referred to the Newark system, is usually correlated with 

 the Rhaetic of the Old World, though Eastman in his recent 

 paper on the Triassic fishes of Connecticut (Bulletin 18, 

 Conn. Geol. & Nat. Hist. Survey, p. 32), in speaking of the 

 fish fauna, says: "The Triassic fish fauna of eastern North 

 America is of a more or less manifold nature, and corresponds 

 in a general way to the interval between the uppermost Mu- 

 schelkalk and the basal division of the Keuper in the Mediter- 

 ranean region." The English footprints found in the Lower 

 Keuper Storeton quarry near Liverpool, however, do not 

 resemble those of the Connecticut valley in a single instance, 

 though a three-toed dinosaurian track described by Sollas as 

 Bronlozoum thompsoni which was found at Newton Nottage, 

 Glamorganshire, and referred to the Lower Keuper (Magnesian 

 Conglomerate), shows affinities with those in the Connecticut 

 fauna. 



According to the usage of the United States Geological 

 Survey, the non-committal name of Jura-Trias has often been 

 applied to the strata in North America, and as I shall show, 

 the very distinctive dinosaurian fossils are confined to the 

 upper portion of the Newark system both in the Connecticut 

 valley and in New Jersey, while in the lower beds creatures of 

 very different rank predominated. 



In a region of the classic interest which envelops the Con- 

 necticut valley, embracing as it does some of our most vener- 

 able seats of learning, and cradling some of America's greatest 

 geologists, it is not surprising that the discussion as to the 

 origin of the Newark rocks should have been animated. The 

 theories of the method of deposition vary all the way. from 

 submarine, through estuarine to continental, and involve a 

 considerable range of climatic conditions as well. 



Emerson, in the Holyoke Folio (1898), p. 8, discussed the 

 origin of the Newark deposits in the Connecticut valley as 

 follows : 



" The events of the Paleozoic age, constituting a prolonged 

 history of geographic changes, had come to a close, and a land 

 not greatly unlike the present in general configuration had 

 been established, when a new sedimentary record was begun in 

 a bay occupying the position of the Connecticut Valley in 



