550 :^1ES0Z0IC FLORAS OF UNITED STATES. 



bo attached to it, while the cone is quite different from those described 

 I)y Heei- to Leptostrobus. 



The other face of the same cone shows a length of over 4 cm. and 

 a width of about 12 mm. It has nearly the same shape as the side 

 depicted in PI. CX'\\ Fig. 4. It is, however, more nearly entire and seems 

 to narrow slightly at the base and summit. The stout stem retains, 

 however, something more of its original length. This reverse side shows 

 no markings of cone scales, Init presents simply a formless mass of vege- 

 table matter, which represents it and gives its shape and dimensions. 

 This is shown in Fig. 5. Both the specimens were collected by Mr. 

 Bibbins in October, 1895, for the Woman's College of Baltimore, that 

 represented in Fig. 4 being No. 6086, and that in Fig. 5 No. 6149, of 

 the museum of that college. 



Celastropiiyllum obovatum Fontaine. 



PI. CXV. Fig. 6. 



1SS9. CeJastropliyllum olovatum. Font.: Potomac Flora (Monogr. U. S. Geol. Siirv. 

 Vol. XV), p. .307, pi. clxxii, figs. 9, 10, 10a. 



This plant is represented at Vinegar Hill by only one specimen. 

 This, taken in comiection with the specimen of VitiphyUum muUifidnm 

 which occurs on the same piece of shale, seems to connect this flora with 

 that of Federal Hill in Baltimore. The specimen was collected b}' Mr. 

 Bibbins in October, 1895, and l)ears the number 6154 of the museum 

 of the Woman's College of Baltimore. The imprint is that of a small, 

 nearly circular leaf, one side of which is preserved, but the base and 

 part of the other side are wanting. It is shown in PI. CXV, Fig. 6. 



Dryopteris heterophylla (Fontaine) Knowlton. 

 PI. CXV, Figs. 7, 8. 



1889. Aspidium JieteroplnjUum Font.: Potomac Flora (Monogr. U. S. Geol. Surv., 



Vol. XV), p. 96, pi. xiv: pi. xv, figs. 1, la, 2, 3, 3a, 4, 4a, 5, 5a. 

 1895. Dryopteris heteropJi yUa (Font.) Kn.: Bull. U. S. Geol. Surv., No. 152, p. 92. 



A common fern at this locality is a plant that is identical with 

 Dryopteris heterophylla, a form that is characteristic of the Fredericks- 

 burg locality of Virginia. It is preserved here with sufficient distinct- 

 ness to admit of its certain identifiGation. PL CXV, Fig. 7, gives a con- 



