MESA VERDE FORMATION 603 



measured sections are described apart from the sections. The species of 

 each lot are named in the descriptions of the several fields given in the 

 latter part of this paper, and the general grouping of them is presented 

 in the preceding table. This table contains only the names of fossils 

 identified by T. W. Stanton from collections made principally by the 

 writer, althongh a few fossils collected by J. H. Gardner and others in 

 western Colorado and New Mexico have been included. Relatively few 

 of these species have ever been described. This may be of no serious con- 

 sequence for the purposes of this paper, inasmuch as these species seem to 

 have a somewhat restricted geographical distribution in New Mexico, and 

 their nearest known allies occur far to the southeast in Texas; but it is 

 unfortunate that so well developed a fauna as that shown in the foregoing 

 table can not now be made available by proper descriptions and illustra- 

 tions for purposes of correlation as stratigraphic work is extended in the 

 coal fields of New Mexico. A few of the species have been described by 

 Herrick and Johnson and by Shinier and Blodgett, and the names given 

 them will be found in the annotated list of publications in the latter part 

 of this paper, but only those species which have been identified in the 

 collections of the United States Geological Survey are included in the 

 table. 



Fossil plants occur at certain horizons in the Mesaverde of all the coal 

 fields in central New Mexico, and in some places they are numerous and 

 well preserved, but fossil plants seem to be rare in the Mesaverde of 

 northern New Mexico and southern Colorado. Unfortunately, a large 

 part of the flora consists of undescribed species, so that the lack of spe- 

 cific names in the following table might be interpreted as indicative of 

 poor material, whereas in reality it indicates undescribed species of beau- 

 tifully preserved leaves. Unlike the invertebrates, whose nearest allies 

 occur far to the south, some of the fossil plants are specifically identical 

 with those from some of the coal fields to the north and east, and others 

 are so strikingly similar to species found in those fields that they indicate 

 essentially the same age. Thus the flora most nearly like that of the 

 Mesaverde of central New Mexico is found at Point of Eocks, Wyoming, 

 and other localities to the north in rocks of recognized Montana age. 

 The correlation with the older coal-bearing formation of the Eaton field 

 is nearly as perfect, but since the flora of the Raton field is being crit- 

 ically studied at the time of this writing, no final statement regarding 

 the correlation can be made. However, Doctor Knowlton, who has iden- 

 tified the fossils listed in the following table and who is studying the 

 flora of the Eaton field, has kindly made the following statement for 

 use in this paper : 



XLIII— Bull. Geol. Soc. Am., Vol. 23, 1911 



