OLDER POTOMAC OF VIRGINIA AND MARYLAND. 499 



locality at the time of its discovery, on December 5, 1892, is a good 

 example of this plant and occurs in counterparts. This is the one 

 shown in PL CX, Fig. 2. The other specimens from this locaUty were 

 collected on May 14, 1893. Of those from the Mount Vernon locality 1 

 good specimen was obtained on the occasion of its discovery by Professor 

 Ward, on October 16, 1892, 8 on the next visit, Noveml^er 6, 1892, includ- 

 ing the one represented in Fig. 3, and 3 on May 14, 1893, including that 

 shown in Fig. 4. 



POPULOPHYLLUM MINUTUM Ward 11. Sp."' 



PI. evil, Fig. 9. 



Professor Ward has, on the label accompanying it, compared one 

 small specimen from the Mount Vernon locahty with Velenovsky's 

 Cissites crispus. The leaf resembles Populus potomacensis in shape and 

 size, but the nerves are different. The specimen was collected on Novem- 

 ber 6, 1892, and occupies the opposite side of the most complete counter- 

 part of Celastrophyllum Brittonianum treated above. 



Populus auriculata Ward. 



PL CX, Fig. 5. 



189.5. Populus auriculata Ward : The Potomac Formation (Fifteenth Ann. Rep. U. S. 

 GeoL Surv., 1893-94), p. 356, pL iv, fig. 4. 



This species was first found by Professor Ward, and was described 

 by him. The form given in Fig. 4 of his paper is one of the best 



e Professor Fontaine returned this specimen without description with the request that I describe it. It 

 has the following character: 



Leaf nearly circular in outline, veiy small, about 16 mm. in length and breadth, coarsely dentate except 

 near the base; nervation somewhat palmate, but central nerve much stronger than the four lateral ones that 

 proceed from the summit of the petiole, these latter forking and anastomosing some distance from the margin 

 and giving off fine nei-villes that cross the meshes irregularly. 



The nervation of this little leaf is in some respects similar to that of the Vitacefe, but there are features 

 that recall Populus. It may represent a small form of that genus. It can not, however, be referred to either 

 of the species of Populus from the Mount Vernon clays, and is a new species. I place it for the present in the 

 extinct genus Populophyllum, its nearest affinities being perhaps with P. reniforme Font. 



The note that I made on the label at the time I studied this Collection is as follows: "This leaf is a 

 Cissites near 0. crispus, probably the same as that figured by Doctor Newberry (Flora of the Amboy Clavs, 

 pi. xhi, figs. 20-23), but not identical with Velenovsky's species." I have not seen the Amboy clay speci- 

 mens, much less the specimen figured by Velenovsky, but judging from the figiu-es on second inspection I 

 would now recede from the statement in my note. The type of 0. crispus from the Cenomanian (Chlomeker 

 Sandstein) of BOhm-Leipa in Bohemia (see Velenovsky, Die Flora der bohmischen Kreideformation, Pt. IV, 

 p. 12, pi. iv, fig. 6; Beitriige z. Paliiontologie Osterreich-Ungarns, Vol. V, Heft I, p. 73, pi. xxvii, fig. 6) is a 

 very different thing from Doctor Newberry's plant. My specimen is nearest to his fig. 20. It also resembles 

 his fig. 22, but that is much smaller. His figs. 21 and 23 are not only different specifically from these, but 

 also from each other. I do not think that Doctor Newberry's plant is a Cissites.— L. F. W. 



