1892.] NEW YORK ACADEMY OF SCIENCES. 143 



Near the southwestern end of Skunnemunk Mountain, about two 

 and one-half miles north-northwest of Monroe, and one-fourth mile 

 southwest of the Seven Springs Mountain House, are the Davidson 

 quarries. The lower quarry is approximately 290' higher than the 

 Cooley quarry, or about 750' A. T. An excavation has been made 

 in the ledge at a place just north of the highway, and the eastern 

 wall of the quarry is ten feet high. Some bluish-gray flagging- 

 stone has been taken out, but a considerable part of the quarry is 

 composed of shaly gray ai'enaceous la3rers. At the northeast corner 

 are two layers containing fossil plants, which are separated by a 

 stratum of the bluish sandstone. The plants are generally in the 

 more argillaceous layers, although specimens poorly preserved are 

 occasionally seen in the coarse, bluish-gray sandstones. In this 

 quarry, which may be called the lower Davidson, specimens of 

 P.riJophi/ton princeps Dn., Calamites sp., and aerial rootlets of 

 Calamites (?) occur. 



A short distance northeast of the lower quarry and a little higher 

 is the Davidson " Coal Mine" quarry, from wliich Professor Martin's 

 plants were collected. The quarry has been opened to a consider- 

 able extent, the wall of rock being twenty feet high on the eastern 

 side. The dip is apparently to the northeast, but on account of 

 false bedding and thinning of the layers it is difficult to determine 

 the amount and direction. Considerable bluish-gray flagging-stone 

 has been removed from this quarry, and in lithologic characters it 

 resembles closely the Hamilton flagging-stone of Ulster and Greene 

 counties. New York. 



No fossils were found except plants, and these are quite abundant 

 in certain layers of the quarry. The most common species is 

 Ptiilophyton princeps Dn. 



The plants collected by Professor Martin probably came from 

 this quarry, and through his kindness the writer has had the 

 pleasure of examining a portion of the collection. Specimens of 

 the Psilophi/fon princeps Dn. from this quarry have been examined 

 by Sir J. Wm. Dawson and Professor D. P. Penhallow, and they 

 agree with the above identification. From Professor Martin's col- 

 lection, specimens of the Lepidodendron, Calamites, and Dadoxylon 

 identified by Dr. J. S. Newberry as L. gaspianum Dn., C. transi- 

 tionis Gopp., and Dadoxylon {ly were submitted to Dr. Dawson. 

 Principal Dawson agrees with Dr. Newberr}" in the identification 

 of the Lepidodendron; the Calamites he would call C. radiatus 

 Brongn., regarding C. transitionis as a synonym of the preceding, 

 and the Dadoxylon he calls the aerial roots of a Calamitc or fern. 



The distribution and range of Calamites radiatus Brongn , also 

 frequently called Bornia radiata (Brongn.) Sch., and Archaeo- 

 caJamities radiatus, (Brongn.) Stur, including Catamites transi- 

 tionis Gopp. as a synonym, are (juite extended, and no attempt has 

 been made to verify the numerous reported identifications of this 



1 Pi-oc. Lye. Nat. Hist., N. Y., vol. i, p. 259; and An. Kept. State Geol. 

 (New Jersey), for 1884, p. 54. 



