TIIH OLDER MESOZOIC OK ARIZONA. 15 



t)()iies was the I'ichcsl in this respect, and the greater i)art of Mi-, lii'own's 

 collection was made within a mile <ii' more of the original localitw 



It will of course be impossible for me to give any adeiiuate account 

 in this place of Mr. Brown's collection of Triassic bones. Suihce it to 

 say that he made an extensive collcM-tion, consisting to a considerable 

 extent of well-recognized bones, some of them entire, others capal)le 

 of having the separated paits brought together, but otliei's, of course, 

 as in the case of Triassic bones the world over, more or less fragmentary. 

 They represent chiefly the Belodont, Hetvrndoiito.suchiis (/(mcl Lucas, 

 mentioned in the first paper, page 323, but teeth and other parts were 

 found that prol)ably belong to ancestral dinosaurs, while one very large 

 scute belongs to the genus Lal)yrintho(lon. The collection was shipped 

 to the National Museum at Washington. It has been unpacked under 

 the direction of Mr. F. A. Lucas, in whose hands it will doubtless be 

 carefully worked up and the results duly published." 



I am very glad to be able to record the success of this expedition 

 from the standpoint of vertebrate paleontology, l)ecause from the stand- 

 point of fossil plants my anticipations were not reaUzed. In a region 

 which contains almost everywhere such an enormous quantity of silicified 

 wood and which consists so largely of sedimentary and definitely strati- 

 fied rocks it was reasonable to suppose that there would be found occa- 

 sional beds at least in which impressions of the foliag(\ fruit, and flowers 

 would be preserved. But the search was almost wholly without success, 

 and the conclusion was reached that for one reason or another the con- 

 ditions for the preservation of the parts of plants which are most essen- 

 tial in the determination of the flora were absent from this entire region. 



The explanation of the absence of plant impressions of the more deli- 

 cate kind is prol)al)l>' to be foimd mainly in the great abundance of gypsum 

 that prevails throughout all these beds, which, as is well known, is almost 

 fatal to the preservation of organic remains. But for it no doubt the 

 vertebrate remains would be much more abundant and complete, and it 

 is onl>- the silicified wood that seems to escape its influence. This latter, 

 however, is mainly deposited in beds of sand, coarse gravel, or conglomer- 

 ate, which, in themselves, ar(> unfavorable to plant impressions. 



"A prclinuimiy rejiort was piiMislicil hy liim ill Science, \. S., Vol. XIV, September 6. H)l)l, p. 370. 



