JURASSIC CYCADS FROM THE BLACK HILLS. 203 



PI. LXII, Fig. 4. Seward's figure of a fine frond of Williamsonia 

 gigas ( L. & H.) Carr., pi. v of the Jurassic Flora of Yorkshire, Part I. 

 Natural size, cf. PL LXII, Fig. 1. 



Note.— PL LXII, Figs. 1-3, and PL LXIII, Fig. 1, are from the 

 University of Wyoming cycads No. 500.39, figured on pi. cxxxviii, fig. 

 2, of the first paper on the Mesozoic Flora. 



JURASSIC CTCADS FROM THE BLACK HIt,I>S. 



On all sides of the Black Hills the Jurassic always immediately 

 overlies the Red Beds and underlies the Lower Cretaceous (Lakota 

 formation of Darton). This last is the source of the great numbers 

 of cycadean trunks that I have described from the Black Hills. These 

 occur about midway of that formation, and below the cycad horizon 

 are various plant beds containing impressions of cycadaceous vegeta- 

 tion. Until i-ecentl}^ no plants except fossil wood had been found in 

 the underlying Jurassic beds, the upper member of which is the Beulah 

 formation (Beulah clays of Jenney), in which occur the Atlantosaurus 

 beds of Marsh. When I made my fourth and last visit to the Yale 

 Museum, in May, 1900, to complete the elaboration of the great collec- 

 tions of cycads that Professor Marsh had so munificently accumulated 

 there, I found one very anomalous specimen that had been purchased 

 for Professor Marsh by Mr. H. F. Wells from a dealer in Hot Springs 

 who had obtained it from a stranger and had no record further than 

 that the man who sold it to him had told him that he obtained it "50 

 miles west of Hot Springs in Wyoming." I named the new species, 

 which it clearly constituted, Cycadeoidea utopietisis, but in the descrip- 

 tion I stated that on the surface there was "an area near the summit 

 covered by what appears to be an outer coating of ramentum, as in 

 the genus Cycadella, more or less obscuring the organs." At the end 

 of the discussion I said: "The patch of ramentum, if such it be, near 

 the summit of the specimen, raises the suspicion that it may belong 

 to the genus Cycadella, and, as all the specimens of that genus thus far 

 known have come from the Jurassic, it is possible that the horizon of 

 the bed holding this specimen may be lower than that of the other Black 

 Hills cycads." I also discussed the probable locality and regarded it 

 as "more probable that the direction was northwest from Hot Springs, 



