REVIEWS 201 



Triassic Life of the Connecticut Valley. By Richard Swann Lull. 

 Connecticut Geol. and Nat. Hist. Survey, Bull. 24. 



The author interprets the environment, both physiographic and 

 climatic, of Newark time in the Connecticut valley, and gives a full 

 discussion of the animal life with descriptions and illustrations of both 

 the fossils and the trails and footprints in these beds. 



The remarkable thing about this fossil field is that actual fossils are 

 exceedingly scarce but trails and footprints are found in marvelous 

 abundance. In actual fossils the invertebrates are represented by only 

 two species of Unto and a single aquatic insect species. The terrestrial 

 vertebrate skeletons are all reptilian, consisting of only two species of 

 phytosaurs, two of aetosaurs, and five of theropod dinosaurs. 



However, the trails and footprints indicate a much greater and more 

 varied fauna. Of the invertebrates, annelids, insects, spiders, scorpions, 

 and fresh-water crustaceans of great variety were doubtless present. 

 The footprints represent two, possibly three, classes of terrestrial verte- 

 brates — amphibia of salamandrine form and also stegocephalians; 

 among the reptiles, lizards, turtles, and dinosaurs, and possibly, also, 

 rhynchocephalians, phytosaurs, aetosaurs, and theromorpha. There 



is no evidence that birds were present. 



C. H. E. 



The Cretaceous-Eocene Contact in the Atlantic and Gulf Coastal 

 Plain. By L. W. Stephenson. Professional Paper, U.S. 

 Geol. Survey, No. 90-J, 1915. "Shorter Contributions to 

 General Geology, 1014." Pp. 155-81, pis. XI-XIX (including 

 2 maps), figs. 13-20 (including map). 

 "The Cretaceous deposits of the Atlantic and Gulf Coastal Plain are 

 separated from the overlying Eocene and younger formations by an 

 unconformity of regional extent"; the unconformity can be traced from 

 New Jersey to the Rio Grande, and from there southward into Mexico. 

 After the Upper Cretaceous sediments were laid down, the sea with- 

 drew to the south and east some distance beyond the present shore-line; 

 the Lower Eocene beds were deposited on a nearly base-leveled surface. 

 The faunal changes that occurred between the deposition of the 

 uppermost Cretaceous and the lowermost Eocene strata were very pro- 

 found; out of 168 species representing 89 genera in the Exogyra costata 

 zone, which includes the upper part of the Selma chalk (uppermost Cre- 

 taceous), 20 or more common genera and practically if not all of the 



