OLDER POTOMAC OF VIRGINIA AND MARYLAND. 485 



WiLLIAMSONIA ? GALLINACEA Ward 11. Sp." 



PL CVII, Fig. 4. 



The supposed Williamsonia is a fragment, showing what seems to he 

 the summit of the peduncle of the inflorescence, with portions of the bases 

 of the bracts. It is not distinct enough to make the generic identification 

 positive. 



The hst given above of the plants obtained from Cockpit Point shows 

 that the horizon is that of the Rappahannock or Fredericksburg beds; 

 that is, near the base of the lower Potomac, corresponding to Professor 

 Ward's Rappahannock series. This is confirmed by the character of the 

 strata, for the fossiliferous stratum is, in lithological character, much hke 

 the basal material of the lower Potom.ac found at Alum Rock, near the 

 town of Fredericksburg. It rests on unlaminated, greenish, sandy 

 material which weathers bright red. This rock matter is characteristic of 

 the bottom beds of the lower Potomac in the northern portion of the 

 formation in Virginia. 



FOSSIL PLASTS FKOJI >EAK WOODBEIDliE. 



Cycadeospermum obovatum .Fontaine. 

 PI. CVII, Fig. 5. 

 1889. Cycadeospermum ohovatum Font.: Potomac Flora (Monogr. U. S. Geol. Surv., 

 Vol. XV), p. 270, pi. cxxxv, fig. 13. 

 Mr. Victor Louis Mason obtained on October 5, 1893, a complete 

 seed of Cycadeospermum obovatum Font, from a cut on the Atlantic^ 

 Coast Line Railroad below (south of) Woodbridge, Va., near the north' 

 end of the cut. This is from the same horizon as the plants from near 

 Lorton, next to be considered. It occurs near the contact with the 

 Cambrian slates. In Monograph XV these slates were spoken of as 

 Azoic, but later investigations show them to be probably Lower 

 Cambrian. 



FOSSIL PLANTS FROM NEAR LOKTON STATION. 



This is the locality formerly known as "Telegraph Station." It 

 was designated by this latter name in Monograph XV, p. 22. The 

 railroad station is at Springman post-office. The spot from which the 



« Professor Fontaine assigned no specific name to this form. The name adopted alludes to the locality.— 

 L. F. W. 



