516 RECORDS 



of rocks along the Hudson, the included schists, and the Tomp- 

 kins Cove Limestone quarries. The third series illustrated the 

 character of the sand dunes of Newburyport and Plum Island, — 

 the dissected drumlin at Great Boar's Head, New Hampshire, 

 and the gneissoid granite with dikes at Isle of Shoals. 



The slides were further discussed by Professor Kemp, Dr. 

 Julien, and Dr. Levison. 



Professor Martin discussed the geology of the Jones' Falls 

 valley, north of Baltimore, Md. The rocks are principally white 

 hornblendic gneiss, cut by pegmatite dikes, — the latter contain- 

 ing many minerals. The crystallines decomposed with great 

 rapidity, forming a reddish soil. Professor Martin also com- 

 mented on the excellent museum of local geology maintained by 

 the Maryland Academy of Sciences, which illustrates all the 

 formations of the State from the base of the Archean to the 

 Catskill. The use of the term Catskill in describing the rocks 

 called by that name in Maryland was called to question, and 

 was discussed by Drs. Call, Hovey, JuHen, Kemp, White, and 

 Professor Stevenson, the latter defining the Catskill as a condi- 

 tion arising at the closing period of the Chemung in certain 

 localities, and not marked by characteristic fossils nor worthy of 

 a position as a division of the geological time scale. 



Dr. Levison exhibited a number of minerals from the pegma- 

 titic development in the Jones' Falls quarries near Baltimore, 

 Md. Among them were albite, laumontite, garnet, epidote, 

 thulite, and zoisite. 



The meeting adjourned at lo P. M. 



Theodore G. White, 



Secretary, 



