Paleontology 68 1 



the Eastern United States" (1893); W. M. Fontaine's "De- 

 scriptions of Fossil Plants from the Great Falls Coal Field, 

 Montana" (1892) ; and notes by the same author on "Fossil 

 Plants from the Trinity Division of the Comanche Series in 

 Texas" (1893). The species described in the latter paper 

 are known as the Glen Rose fossils. From a tabular state- 

 ment it is seen that all the species of Glen Rose fossils 

 hitherto known occur in the Lower Cretaceous, ranging 

 from the Wealden to the Urgonian. The Potomac includes 

 both these epochs. Omitting the species that have no value 

 for fixing the age of the flora, because they are not sufficiently 

 characterized, the author has nineteen for comparison. Four 

 of these are peculiar to the Trinity division ; of the fifteen 

 remaining, no fewer than twelve are identical with plants from 

 the older Potomac, or so near them that nearness in age of 

 the two formations is extremely probable. The circumstances 

 under which the basal Trinity beds were laid down indicate 

 that the fossils entombed in them form a portion of a flora 

 that was established on the land that was encroached upon 

 by the Trinity sea. It is probable that this same flora ex- 

 tended northward to Virginia, where, somewhat later, it was 

 preserved by a similar encroachment. 



The publications on invertebrate animals antedate those 

 concerning fossil flora by almost a score of years, the record 

 showing that Meek's check-lists of North American inverte- 

 brate fossils were issued in 1864. These form part of the 

 " Miscellaneous Collections," and consist of check-lists of all 

 the species of Cretaceous, Jurassic, and Miocene invertebrate 

 fossils of North America which had been described up to the 

 end of 1863. They constitute an important aid in the labor 

 of cataloguing and labeling collections. Meek's lists were 

 supplemented by those of Conrad in 1866, and his in turn by 

 Marcou in 1885 and 1886. 

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