OLDER POTOMAC OF VIKCilMA AND MARYLAND. 50?, 



Zamia WAsiiixcroxiAXA Ward." 

 I'l. ('XL Fi-s. L 2. 



1S'.)5. Zamia WasJii'iijIiniiaiia Wai'd: The Pcildinac I'^n-ination (Fifteenth Ann. l\e]>. 

 U. S. Geol. Sui-v., ls'.i:i-'.)4), p. :!.".(), ])l. il, lig. G. 



Professor Ward, in the work cited, has given an ^account of this 

 plant, and in pi. ii, fig. 0, has depicted a leaflet and what he regards as 

 its fruit. In his description of the leaflet he regards the narrowed poi'- 

 tion as the base. In my opinion this is a mistake, it l)eing the termi- 

 nation of the leaf. Several other fragments of the leafiets of this plant 

 were ol)tained. One of them shows the l)ase pretty well preserved. 

 It narrows like Zamites and seems to have l)een articulated to the stem. 

 This is indicated also by the fact that all the leaflets are detached. 

 Some of the leaflets must have been ver}' large, much surpassing any 

 leaflet of like form found previously in the Potomac flora. Several 

 of the fragments show a maximum width of 15 mm. One fragment, 

 apparently a little more than half of a leaflet, is 10 cm. long. A smaller, 

 entire leaf, probably from the tipper part of the component leaf, was 

 obtained which is only 11 cm. long. This is mtich smaller than most 

 of the leaflets found. This shows the l)ase slightly narrowed and also 

 thickened. The nerves are not very distinct in the leaflets of this plant. 

 They appear to Ije comparatively broad and flat. Eleven specimens 

 of this plant occur in the collections, all from the Mount Vernon local- 

 ity. Six of these were collected on November 6, 1892. These are all 

 small fragments. The remaining five, collected on May 14, 1893, include 

 all those figured and two less complete leaves. 



The above comprise all the fossils found in the Mount Vernon beds 

 up to the present time, 39 species in all. There is little doubt that a 

 good many more might be fotmd in them if sustained search were made. 

 They are sufficient to show that this horizon is, as Professor Ward 

 maintained, an intermediate one between the Rappahannock and the 

 Acpiia Creek beds. 



" Two other fine specimens of leaves of tliis plant, both in counterparts, were found at the same time 

 and place as the one figured by me, and in view of Professor Fontaine's statements I thought best to figure 

 them. The broad one represented in PI. CLXXVI, Fig. 1, is t_ypical, but shows the complete tip drawn out 

 to a long, narrow, curved point. The other, shown in Fig. 2, is a much narrower leaf, and I was in doubt 

 whether it belonged to the same species. Professor Fontaine returns it without comment, with the name on 

 the label as I had written it. I therefore conckide tliat he considers it a narrow form of this plant. This 

 also shows tlie tip complete. Tlie crooked shape of the leaf nuist be ascribed ti) distcirtion from pressure. — 

 L. F. W. 



