516 MESOZOIC FLOKAS UF UNITED SlATEs. 



LOCALITIKS IX THE DISTUICT OF COLl'MBIA. 

 KISSII, l>I,A>TS UtOM SIXThKMII STRKKT. 



[PI. EXXX, No. 122.] 



The fossil plants next to be noticed come from Washington, D. (\, in 

 an excavation luiido on Sixteenth street (see pp. 382-383 and Fig. 10, on 

 p. 387). They occur on the east side of the cut, 6 feet alcove its liase. 

 The material belongs to the basal strata of the Lower Potomac, probably 

 somewhat higher than the fossils from near Lorton. The locality is not 

 favorable for collecting good specimens, as the plants are contained in 

 lumps of cla}' which seem to have been torn up and transported. Hence 

 it is probable that their original position was at a somewhat lower horizon. 



Determinable plants were collected by Professor Ward and Mr. Victor 

 Mason on iMay 7, 1893, and by Professor Ward and myself on July 14, 

 1893. They all occurred in the Rappahannock clays, No. 2 of the section 

 on p. 386, overlying the cross-bedded sands. The following species were 

 found : 



Athrotaxopsis tenuicaulis Font 11 specimens. 



Nageiopsis angustifolia Font 1 specimen. 



Podozamites distantinervis Font. ? - - - 2 specimens. 



Thyrsopteris angustifolia Font - - - 2 specimens. 



FOSSIL I'l.ANTS FROM THK \KW RKSKRVOIK. 



[Pi. LXXX, No. 121.] 



The locality designated "new reservoir" is situated in the city of 

 Washington. The excavation made for this reservoir reached and cut into 

 the basal beds of the Lower Potomac. The plants in the collection come 

 from two spots near the base. One is on the east side, nearly opposite the 

 shaft, and above the lignite bed at the bottom of the reservoir. The 

 other is on the west side near the shaft, 6 feet above the bottom of the 

 reservoir. These are practically on the same horizon, which is about the 

 same as that of those from Cockpit Point and Lorton. 



The two localities were discovered by Professor Ward on September 

 18 1892." The one on the east side near the bottom of the reservoir 

 yielded most of the plants. Nearly all the specimens collected at that 



"The exact positions of botli localities are descriljcd in tlie liistoriial |)art of this paper (see pp. 379- 

 380).— L. F. W. 



