PREGLACIAL CONDITIONS AND LIFE 203 



is quite uncertain; in some instances the time of deposition may have been 

 much later. A few of these supposed preglacial deposits may here be 

 considered. 



a. FISH-HOUSE CLAY FLORA AND FAUNA, NEW JERSEY 



Many years ago. Prof. E. D. Cope obtained from a deposit at Fish-house, 

 Camden County, a number of fresh-water river mussels (Unionida), associated 

 with the remains of an extinct horse, which were described by Lea 19 and 

 referred to the Cretaceous horizon. Later, 20 Whitfield fully described and 

 illustrated these species and added two more, considering them as belonging, 

 stratigraphically, near the base of the New Jersey Cretaceous. Prof. Cope 21 

 and Dr. C. A. White, 22 in later publications, have considered the deposits as 

 of Pliocene or Pleistocene age. Dr. H. A. Pilsbry 23 considers the deposit as 

 "either interglacial or preglacial and a divergence of a part of the species from 

 the most allied forms, as well as the fact that the fauna was an abundant one, 

 composed of large and well-developed individuals, point rather to preglacial 

 than to interglacial conditions." 



i. Section of Strata at Fish-house 2 *' 

 Well section 



1. Top soil Wi feet 



2. Moulding sand \ X A " 



3. Fine gravel 4 " 



4. Fine clayey sand.., 4 " 



5. Heavy gravel with large pebbles... \ l A " 



6. Black or blue clay S]A, " Equus above shell bed; Unios near base of 



bed; plants thruout bed. 



7. Ironstone crust Yi " 



8. Dark sand 2J4 " Cross bedded. 



9. Fine light sand 4 " 



10. Dark sand 3 



11. Light sand and gravel 3 " i 



Height of section 33 feet 



The cross bedded sand stratum under the clay deposit indicates that it was 

 laid down in "a former Delaware River bed, the river at that time flowing in a 



"Proc. Phil. Acad. Sci., 1868, p. 162. 



" Brachiopoda and Lamellibranchiata of the Raritan Clays and Greetisand Marls of 

 New Jersey, pp. 243-252. 



a Trans. Amer. Phil. Soc, XIV, pp. 249-250, 1869. 



■ 3rd. An. Rep., U. S. G. S., 1883. 



a Proc. Acad. Nat. Sci. Phil., 1896, pp. 567-570. 



u Woolman, Geol. Surv. New Jersey, An. Rep., 1896, p. 247. 



