548 MESOZOIC FLORAS OF UNITED STATES. 



Cladophlebis falcata Font. ? 2 specimens. 



Dryopteris angustipinnata (Font.) Kn. *? 1 specimen. 



Dryopteris fredericksburgensis (Font.) Kn 1 specimen. 



Dryopteris heterophylla (Font.) Kn .. . 8 specimens. 



Ginlvgo 1 acetaria Ward n. sp 1 specimen. 



Leptostrobus longifolius Font . 26 specimens. 



Nageiopsis heterophylla Font 1 specimen. 



Nageiopsis longifolia Font 25 specimens. 



Nageiopsis recui'vata Font. ? 1 specimen. 



Pecopteris vu-giniensis Font 8 specimens. 



Selaginella marylandica Font. n. sp . 1 specimen. 



Sphenolepidium parceramosum Font 2 specimens. 



ThjTsopteris nervosa Font. ? 4 specimens. 



Thyrsopteris rarinervis Font J _- _ _ 2 specimens. 



Vitiphyllum multifidum Font 1 specimen. 



Williamsonia 1 Bibbinsi Ward n. sp 1 specimen. 



Zamites tenuinervis Font. ? _, 1 specimen. 



Abietites macrocarpus Fontaine. 



PL CXV, Figs. 2, 3. 



1889. Abietites macrocarpus Font.: Potomac Flora (Monogr. U. S. Geol. Surv., Vol. 

 XV), p. 262, pi. cxxxii, fig. 7. 



Eighteen cones that were apparently of great size and that seem to 

 be referable to this species occur among the Vinegar Hill collections. They 

 are usually very poorly preserved, so as to show only vague indications 

 of an axis with often detached scales, placed so as to show a former 

 attachment to the axis. The scales must have been thin and long, 

 overlapping one another along the axis. These cones are much larger 

 than those supposed to belong to A. ellipticus, and the proportionally 

 great number of them would indicate that this was one of the most 

 important and abundant plants in the flora of the Vinegar Hill locality. 

 PL CXV, Figs. 2, 3 represent two cones, both of which occur on the 

 same rock fragment. They may suffice to give an idea, the one of the 

 length of the cone and the other of the length of the scales. This speci- 

 men was collected by Mr. Bibbins on September 1, 1896, and is No. 6333 

 of the Woman's College of Baltimore, but a note on the label states that it 

 was presented to the Maryland Geological Survey by the Woman's College. 



The plant occurs, although rarely, in the lower portion of the lower 

 Potomac of Virginia. 



