540 FLORA OF THE LARAMIE GROUP. 



tbc typical fiicoid, with its verrucose surface, olteu project. These in- 

 flated concretions vary in shape from cylindrical to globular, and when 

 the projecting fucioid is absent we have the simple spherical concretion 

 which is familiar to all. By careful selection I succeeded in securing a 

 good series of these forms, which seem very clearly to point to the fn- 

 coidal origin of this class of concretions. 



Point of Kocks has become a familiar name to paleontologists since 

 the discovery there of a thin bed of white sandstone containing very 

 perfectly preserved specimens of fossil plants that proved, upon ex- 

 amination, to constitute a florula somewhat different from that of any 

 other locality in the West. This spot was visited and most of the much 

 discussed forms — Pistia corrugata. Lemna scutata, Trapa microphylla, 

 Ficus asarifolia, etc. — were found, but little was added to the previous 

 discoveries of others. This locality is a mile or more east of the station, 

 and is situated quite high up the cliff, which is here steep, and the place 

 is difficult of access. The lower ])ortion of the cliff at most points near 

 the railroad consists of white fucoidal sandstone, the fucoids being in 

 a much less perfect state of preservation than at Black Buttes and more 

 concretionary. Below the fucoidal sandstone, at one point northwest 

 of the station, there occurs a bed of light gray or nearly lavender coloi-ed 

 clay containing fragments of ferns and conifers, together with Pistia 

 vorriKjata, Sequoia bi/ormis, and other species found in the white sand- 

 stone stratum last described. It does not seem possible that this stra- 

 tum can dip sufficiently to the west to bring it to the base of the blnft', 

 and no evidence of a fault was discovered. The color and fine-grained 

 character of the rock are similar, but the mineral constitution is very 

 different in the two beds, so that the question as to their jwssible strati- 

 graphical identity is still open. If the fucoidal sandstone forms the 

 base of the Laramie, these chiy beds must occui)y the summit of the 

 Cretaceous. 



Above the massive white sandstone are several coal seams of good 

 quality. They vary in thickness and disappear at some points so as 

 to vary also in number, but about Ave such seams can usually be seen. 

 Very few dicotyledonous or i)henogamous plants exist in the strata 

 between the coal beds, although these resemble those at Black Buttes 

 in all other respects. On the contrary, the fucoids abound throughout 

 all these strata, including those that overlie the highest coal beds. 



Atone point, nearly opposite the station to the north, a bed was discov- 

 ered which contained fine specimens of dicotyledonous and other i)lants. 

 This bed is located just above the lowest coal seam, and is about half 

 way trom the base to the summit of the escarpment. The plants seemed, 

 therefore, to occupy a jiositiou very similar to those at Black Buttes, 

 and they occui' in the same hard gray very arenaceous limestone. They 

 were found only at this one point and in a single layer a foot or more 

 thick, and rocks a few feet distant in either direction were barren of 

 them. This llorula proved very interesting and yielded a number of 



