206 MESOZOIC FLORAS OF UNITED STATES. 



This is a much less complex section than obtains southward from 

 Hulett in the direction of Newcastle, in which direction the Beulah 

 shale series especially is more highly developed than elsewhere about 

 the hills. But it is representative. That somewhere near bed No. 5 

 in the Beulah shales cycads are found is proved by several specimens 

 which occur in connection with numerous remains of large saurians on 

 the Anderson ranch, near the head of Skull Creek, 4 miles south of 

 Inyankara Mountain. Both the fossil bones and the cycads, as well 

 as much silicified wood, plainly belong near the base of the best marked 

 shale seen at this point. 



These cycads belong to the genus Cycadella, and are the first to 

 be definitely located in the lower fresh-water Jurassic of the Black 

 Hills. The fine trunk No. 727 of the Yale collection, named by Professor 

 Ward Cycadella utopiensis, and originally labeled as having come from 

 "50 miles west of Hot Springs," a very unlikely locality, doubtless 

 came from the Inyankara Mountain country. These specimens have 

 precisely the type of preservation seen in thjC Cycadellas from the Freeze- 

 out Hills of Carbon County, Wyo. Both weather white and fracture 

 black, with the same characteristic surface and shades, as do also the 

 segments of silicified tree trunks not only common to both these cycad 

 localities, but plentiful also on the eastern side of the hills. Not alone, 

 therefore, from the general character of the Beulah shales of the east- 

 ern hills, but from the testimony of the most striking forms of animals 

 and plants as well, must we consider them the easterly extension of 

 the cycad horizon of the Freezeout Hills. A few feet over this horizon 

 I believe Professor Marsh's Jurassic mammal quarries to have been 

 located, and the cycads of the Blackhawk and Minnekahta localities 

 in South Dakota must occur from 75 to 125 feet higher. The preser- 

 vation and character of Professor Ward's Cycadeoidea heliochorea from 

 9 miles northwest of Sundance prove that it is a species belonging in 

 the group of cycads obtained in the Minnekahta region, and that it has 

 doubtless come from the same general position, though the specimens 

 thus far obtained, like the great majority of the cycad trunks, were not 

 found actually in place. 



The free development of ramentum and the uniformly small size of 

 the older or Cycadella series, as compared with the younger and larger 



