No. 403.] REVIEWS OF RECENT LITERATURE. 609 
remaining seventeen belong to the angiosperms. Special interest 
centers in the very large number of cycads, — twenty-five species in 
all, — which were obtained in a remarkably fine state of preservation. 
Of these, twenty species belong to the Cycadoidea, the majority of 
the specimens (126) belonging to the Marsh collection of the Yale 
Museum. 
A critical comparison of the flora of the various horizons with cor- 
responding types and formations elsewhere in America and Europe 
leads the author to the unqualified conclusion that “the sandstones 
of the Black Hills belong to the Dakota group proper, or No. 1 of 
Meek and Hayden, while the recent contention that the cycad and 
other plant-bearing beds form a part of the Jurassic may be regarded 
as definitely overthrown.” D. P P 
Fossil Cycads.!— Professor Lester F. Ward continues his studies 
of fossil cycads by a notable contribution to the Washington Academy 
of Sciences on twenty new species from the Jurassic of Wyoming. 
This material first came to notice in 1898, through Professor O. C. 
Marsh, and since then a large amount of additional material in the 
form of well-preserved trunks has been obtained. It is a noteworthy 
fact that these fossils not only represent new species, but they also 
represent an entirely new genus, for which Professor Ward proposes 
to use the name of Cycadella. The chief points of contrast with the 
cycads of the Black Hills are to be found in the relatively small, 
bulbous, subspheroidal, or subconical trunks, which are encased in a 
layer, 5-15 mm. thick, of dense tissue consisting of a chaffy ramen- 
tum, which arises from the leaf bases and becomes matted so as to 
form a thick outer covering. D. P. P. 
Fossil Cycads.? — The very remarkable collection of cycads from 
the Black Hills and other localities, brought together by the late Pro- 
fessor Marsh and now to be found in Yale Museum, has led Mr. G. R. 
Wieland to supplement the admirable studies of Professor Ward by 
à more detailed macroscopic and microscopic examination of these 
plants in all their parts. His preliminary studies give important 
details respecting the character of the inflorescence, the structure of 
! Ward, Lester F. Description of a New Genus and Twenty New Species of 
Fossil Cycadean Trunks from the Jurassic of Wyoming, Proc. Wash. Acad. Sci., 
? Wieland, G. R. A Study of Some American Fossil Cycads, Amer. Jour. Sci., 
1899, vol. vii, pp. 219, 305, 384- 
