MiLLWARD : Fossils from Meadville, Pa. 



481 



is visible. Probably less than one per cent, of the i)ebbles of the 

 drift in this'region were derived from Archaean rocks, and the remain- 

 ing debris consists of fragments of sandstone, chert, and limestone. 

 Pieces of shale and sandstone bearing Chemung fossils are most 

 abundant. These pebbles contain such characteristic species as Spi- 

 rift'.r disjunctus, Reticiilaria prceinatiira, Camarotcechia contracta, Pro- 

 ductella lacrymosa, AtJiyris angelica and Leiorhynchus viesacostale. 

 No attempt was made to make a complete collection from this class of 

 pebbles. Less abundant than these sandy pebbles, but still (juite 

 common, are fragments of fossiliferous chert, while the pebbles of lime- 

 stone make up an insignificant portion of the drift. Practically all 

 the fossils in the cherts are silicified, and while many of them are 

 considerably water-worn and rounded, many fine specimens may be 

 obtained. With but few exceptions the cherts have been much 

 weathered since transportation to this region. The flint has decom- 

 posed to a white chalky material, and occasionally a delicate coral is 

 found entirely freed from the matrix, a condition in which it could 

 not possibly have withstood the rough usage of ice transportation. 



List of Fossils Found in the Limestone and Chert Pebbles 



OF THE Wisconsin Drift. 



Stromatoporella granulata, 

 S. tuberculata, 

 Stromatoporella sp., 

 Favosites hemisphericus, 

 F. canadensis, 

 F. clausus, 

 F. emmonsi, 

 F. epiderinatus, 

 F. limitaris, 

 F. nitellus, 

 F. placenti/s, 

 F. tuberosus, 

 F. iurbinatiis, 

 Favosites 2 sps. , 

 Aulopora cormita, , 

 A. serpens, 



Romingera umbelifera, 

 Syringopora hisingeri. 



Cystiphyllum sulcation, 

 C. vartans, 



Eridophyllum verneiiilaiiuin, 

 Synaptophylluin siincanse, 

 Streptelasma 3 sps., 

 Heliophyllum corniculutn, 

 H. ha Hi, 



Zaphrentis cotivoluta, 

 Z. elegans, 

 Z. gigantea, 

 Z. prolific a, 

 Z. simplex, 

 Z. spissa, 



Stropheodonta perplana, 

 S. hemispherica, 

 S. inceqiiisiriata, 

 LeptcBna rhoviboidalis, 

 Schuchertella chemungensis, 



