OLDER POTOMAC OF VIRGINIA AND MARYLAND. 483 



FOSSIL PLAXTS FROM COCKPIT POIXT. 



Cockpit Point was not known to yield fossil plants until after the pub- 

 lication of Monograph XV. This locality is on the Potomac River. The 

 Coast Line Railroad passes through a cut of considerable depth, situated 

 immediately on the river. This cut has exposed an irregular clay lens 

 inclosed in the Potomac sands and lying about 30 feet above the water. 

 This lens is quite limited in extent, and where it is thickest is only about 

 2 feet thick. The material is a sandy clay, now hardened to a rough shale, 

 with poor cleavage. It is not well adapted for the preservation of por- 

 tions of plants of large size. As it is embedded in coarse sand and gravel, 

 the water making the deposit was exposed to strong movements which 

 tended to break up the fossils. This shale is full of plant remains and, if 

 care is exercised, many identifiable forms may be obtained, although in 

 small fragments. 



In April, 1891, Mr. David White collected here two specimens showing 

 traces of Glyptostrobus (Taxodium) brookensis. Some of the material from 

 the cut was thrown on the bank of the river, and in this most of the fossils 

 were obtained. The principal collections from this point was made l^y 

 Professor Ward and myself in a single visit on July 27, 1893, lasting 

 only an hour or so, with no expectation of finding fossils, hence it can 

 not be taken as exhaustive. Indeed, under the circumstances, it is sur- 

 prising that so many species, in such distinct forms, were found. Most 

 of the fossils were collected from the dumped material, but some from 

 the strata in place. As stated, the material is very unfavorable for the 

 preservation of good specimens; still, a considerable number of plants, 

 as may be judged from the following list, was obtained in the short 

 time devoted to collecting them. Four specimens occur in the collections 

 made by Mr. Bibbins for the Maryland State Geological Survey in May, 

 1897. The following is the list of species collected here. With the 

 exception of Feistmantelia, none of them are new, having been described 

 in Monograph XV. 



Dioonites Bucliianus (Ett.) Born 4 specimens. 



Diyopteris heterophylla (Font.) Kn 3 specimens. 



Equisetum virginicum Font. ? 2 specimens. 



Feistmantelia vii-ginica Font. n. sp 4 specimens. 



Glyptostrobus (Taxodium) brookensis (Font.) Ward 2 specimens. 



Nageiopsis heterophylla Font 1 specimen. 



