OLPKU POTOMAC OF VIRGTXTA AND :\IARYLANn. 507 



<riv(Mi in thai li.iiure. The orifjinal margin of the leaf is retained only in 

 tlic Ict'l-han.l upper portion. Hciv there is an iiuHcation of a I'ather 

 shaUow lol)(". in wliich lauls a secondary nerve that is considerably 

 stronger tlian any of the otliers sent off from tli(> mi(h-il). The latter is 

 rather slender for a leaf of this size and ends in what appears to Ije a 

 terminal lobe, which is only partially preserved. The right-hand marghi 

 of the leaf is not preserved, so that if a lobe onvv existed on that side it is 

 not visible now. That none such existed is indicated by the fad that 

 no strong secondary nerve is sent off on thai side corresponding to the 

 one on the left-hand side, which ends in the lateral lobe. The sinus made 

 by the left lobe with the tenninal lobe is more open than that found in 

 ,S. hUobalnm figmvd on 1)1. clxiv of Monograph XV, and indeed it is 

 more like that of a Liriodendron. The specimen is No. 8437 of th(> 

 Maryland Geological Svu'vey. 



Seqioi.v ( iNFEHNA Ward nom nov." 



1SS9. Sequoia species ( Font.: Potomac Flora (Moiiogr. V. H. Geol. Surv., Vol. XV), 

 p. 24S, pi. cxvi, fig. 7: pi. exxxii, tigs. 2, 5, (i. 

 There are in the collection two dissected cones with a few scales 

 attached that exactly resemtile the specimens described in Monograph 

 XV as "Seciuoia species'?" and figured on pi. exxxii, in figs. 2, 5, 6. 

 This is a very well characterized cone, easily distinguished from any other. 

 It is known to occur only in the Aquia Creek beds, and although it can not 

 be assigned to any species founded on leafy branches, and hence was left 

 undetermined, it is none the less of value in indicating the age of the 

 strata containing it. The specimens bear the numbers M. G. S., 8 54, 

 8465. 



Sphenolepidium Sternbergianum DEN.SIFOLIUM Fontaine. 



PI. CXII, Fig. 1. 

 1889. ST)henolefidium SteTnlergianum densifoliuin Font.: Potomac Flora (Monogr. 

 U. S. Geol. Surv., Vol. XV), p. 261, pi. cxviii, fig. 7; pi. cxxi, figs. 5, .5a, .5b, 

 7, 7a, 9, 9a; pi. cxxv, figs. 2, 2a, pi. cxxLx, fig. 3; pi. cxxx, figs. 1, la; pi. 

 cxxxi, figs. 1, la-lc, 3, 3a; pi. exxxii, figs. 4, 4a. 



"These, as Professor Fontaine says, are well-characterized cones and scales, recognizaljle wlicicvor found, 

 and therefore of diagnostic value in determining age. The fact that they can not l>e identified with .species 

 known hy tlie foliage doe.s not seem to be a sufficient reason for not assigning to them a speciiic name. The 

 name adopted relates to the locality now being treated.— L. F. W. 



