PREGLACIAL CONDITIONS AND LIFE 207 



in the Pensauken at Falsington, Pa., a few miles north of this district. Material 

 much like the Pensauken occurs up the Delaware as at Raven Rock, at much 

 higher levels (200 feet), seeming to point to the direction whence the material 

 came. At least one distinctly glaciated bowlder has been found at Raven 

 Rock. As already indicated, the material of the tributary valley phase of 

 the formation had a different and more local source. " 



"The blocking of the minor post-Lafayette channels in later Pleistocene 

 time produced ponded areas in which were laid down the thick deposits of 

 black clay so typically developed at Fish House and at numerous other points 

 toward the south, through New Jersey, Delaware, and Maryland. ' m 



Fuller 34 refers the Pensauken to the pre-Kansan (Nebraskan) stage and it 

 seems best, all facts considered, to place the age of these beds, for the present 

 at least, as antedating the first glaciation (Nebraskan or Jerseyan) which, per- 

 haps, was the cause of the extinction of the biota. 



b. PORT KENNEDY CAVE FAUNA AND FLORA, PENN. 



At Port Kennedy, Montgomery Count}', Pennsylvania, in a cave containing 

 extensive bone deposits, a large and varied fauna and flora was discovered many 

 years ago. It is believed to be contemporaneous with the Fish-house clay 

 beds. 35 Osbom 36 considers this fauna as early mid-Pleistocene, but with 80 

 per cent of the mammalian fauna extinct, it would seem to be more logically 

 referred to late Pliocene, as suggested by Hay. 37 The insects are all extinct. 3 * 

 In a later paper 39 Hay expresses the opinion that the Port Kennedy fauna is 

 the equivalent of the Aftonian beds of western Iowa. As the question is still 

 unsettled, the biota will here be considered as antedating the first glacial period 

 (Nebraskan or Jerseyan). 



The biota of the Port Kennedy deposits contain 13 species of plants and 

 70 species of animals, as noted below. 4;l 



Plants 



Querent alba Phins rigida 



" palustris Carya alba 

 " macroearpa " porcina 



Fagus ferrug'mea Ampelopsis quinquejolia 



Corylus americana Crataegus crus galll? 

 Primus species " species 



Sphagnum species 



33 Op. cit., p. 19. 



34 Amer. Geol., XXXII, pp. 308-312, 1903. 



35 Woolman, op. cit. 



58 Bull. U.S. Geol. Surv., No. 361, p. 84. 



37 Science, N. S., XXX, p. 892, 1909. 



"Scudder, Amer. Journ. Sci., (iii), XLVIII, p. 181, 1894. 



39 Smith. Mis. Coll., LIX, No. 20, p. 15. 



M Cope, Journ. Phil. Acad. Sci., XI, pp. 193-289, 1899. 



