A New Cycad. 393 



same genus, as Mr. Carruthers has already concluded. As 

 far as species is concerned, the Dakota form differs at sight in 

 the relatively small number of leaf-scars and their verv much 

 greater size, as well as in the fact that the flower-buds (?) are 

 few, large, pedicellate, and almost entirely exterior to the leaf- 

 base armament. As, for the Maryland species, no microscop- 

 ical characters are given, no comparison relative to the fibro- 

 vascular bundles can now be made. Furthermore there is in 

 the Dakota species no indication of a lateral terminal bud. As 

 to the geologic age to which the Dakota fossils belong, the 

 great similarity between the eastern and western specimens 

 would seem to indicate practical identitv of horizon so that 

 B. dacotensis indicates for us the equivalent in Dakota of the 

 Potomac formation, whatever that mav be.^ 



In external form, the perfect specimens of this fossil remind 

 one very suggestively of the pitted stems of a modern Macro- 

 zamia spiralis Miquel, from Australia. The most conspicuous 

 external difference lies in the peculiar character and position 

 of the fruit- or flower-buds in the fossil species. It is to be 

 regretted that in this part of the world material is not just now 

 at hand for more exact comparison. Australia is a Mezozoic 

 land and a close resemblance between our fossils and existing 

 Australian species would not be surprising. 



Special thanks are due Hon. Thos. Wright, of the C, R. I. 

 & P. railway, and Mr. J. Francis, Gen. T. & P. Agt. of the 

 B. & M. railway in Nebraska, for special assistance in the 

 conduct of these investicrations. 



o 



lozva City, lo^va, September, iSgj. 



1 More recent investigations of the question of geological horizon lead to the 

 undoubted conclusion that the fossils are Cretaceous and come from the sand- 

 stone beds called by Meek, and Havden the Dakota group. — Xov. i6tk, iSgj. 



