THE OLDER MESOZOIC OF ARIZONA. 29 



THE MOENGOPIE FORMATION. 



These beds have proved almost entirely barren, no fossil bones 

 ha^dng been found in the calcareous marls of the lower part and no 

 fossil wood anywhere in the formation. It is, however, proper to remark 

 that in the bed of the Little Colorado River about 3 miles below Tanners 

 Crossing, on the surfaces of . certain flags that underlie the conglomerate 

 member, and which I had therefore referred to the Moencopie beds, there 

 were found impressions of coniferous twigs and short stems, showing, 

 however, very little structure. In some "cases the impressions showed 

 that the branches surrounded the stems in the form of whorls. At first 

 they recalled impressions of Equisetum, but fuller investigation showed 

 that they were coniferous stems, with the characteristic whorled branch- 

 ing of the Araucarian type, to which the fossil wood of this region prob- 

 ably also all belongs. As such these vague impressions have great value 

 in showing that this type of vegetation continues to be found in the 

 lowest beds in which any plants occur. The question whether these 

 flags actually belong to the Moencopie beds is, however, an open one. 

 At the time of our discovery I had no doubt on this point, but after 

 finding the transition beds on Red Butte and in the Little Colorado 

 Valley, it becomes possible to refer some portions of the beds that underlie 

 the true conglomerates in the lower region to the conglomerate member. 

 But it thus becomes scarcely more than a question of names and no 

 longer raises a serious problem. 



There is only one other reported fact that need be considered in 

 this connection. Mr. P. C. BickneU, who was my guide in the region 

 of Red Butte, and who has spent much time in studying the rocks of 

 that region, informed me that he once found in the light-colored cal- 

 careous sliales at the base of the butte some faint impressions of fern 

 leaves, which were for the most part too frail to be transported, but 

 that there was one which he took to the Anita mine and compared 

 with certain figures in the few books at hand, and it seemed to him 

 nearest to the figures of some species of Callipteris. The specimen, 

 however, ultimately disintegrated and was lost. On the occasion of 

 our visit he took me to the place and we made diligent search for other 

 specimens, but nothing of the kind could be found. If the species was 

 really a Callipteris it would indicate a Paleozoic age, but as Mr. Bicknell 

 had read in the books that treat of Red Butte that it was a Permian 



