238 T. C. Brown — Fauna from Chappaquiddick Island. 



in these Cbappaquiddick deposits, e. g., Modiola, Glycymeris, 

 are also among the most abundant in the English deposits. 

 These same genera, although represented in the Atlantic and 

 Gulf provinces, are there more sparsely distributed and occur 

 with other more abundantly represented genera that appear to 

 be altogether wanting in the Chappaquiddick deposits. 



A comparison of this Chappaquiddick fauna with other 

 Eocene faunas indicates that it is of lower Eocene age, the 

 species most closely resembling those found in this fauna being 

 found in the lower beds of the Atlantic and Gulf provinces, 

 the Tejon of California and the lower beds o£ England. These 

 deposits may possibly be of the same age as the Shark River 

 beds of New Jersey, but being deposited in a region separated 

 from this have no forms in common with it, but such correla- 

 tion could be only conjecture. As the correlation of the well 

 known Eocene deposits is even yet very uncertain, it is unnec- 

 essary and impossible to place these beds any more definitely 

 than simply to say they are lower Eocene. 



Columbia University, New York City. 



EXPLANATION OF PLATE VIII. 



Figure 1. — Modiola vineyardensis p. 232 



Figure 2. — Modiola hollicki p. 232 



Figure 3.— Corbula Whitfieldi.. p. 233 



Figure 4. — Turritella sp. ? - p. 234 



Figure 5.— Terebra sp. ? - p. 235 



Figure 6. — Terebra juvenicostata p. 235 



Figure 7. — Odostomia semicostata p. 235 



Figure 8. — Odostomia crenulata _ p. 235 



Figure 9. — Genus ? sp. ? p. 236 



Fcgcjres 10 and 11. — Anomia simple xif or mis p. 233 



Figure 12. — Anomia paucistriata _ p. 234 



Figure 13. — Glycymeris sp. ? _ p. 234 



