GEOLOGY. 337 



in this lagoon the smaller fishes lived in great numbers, and, as their teeth 

 proved, lived on vegetables ; on these, which were of the genera Pcdwoniscus, 

 Amblypterus, Mekokpis, &c., the Codacanths, which were carnivorous, sub- 

 sisted ; these in turn becoming the prey of the great MegaMcfdhys and of the 

 sharks. These facts he inferred from the great abundance of the coprolites of 

 the larger fishes, composed almost entirely of the scales and bones of the 

 smaller species which had served them for food. Probably, this lagoon com- 

 municated with the open ocean, where the sharks and rays, &c., lived that it 

 was evidently favorite feeding ground with them that by some means the 

 entrance was stopped the lagoon dried up, partially at least and their dying 

 in great numbers about the same time furnished us with so many beautiful, 

 unmutilated specimens of old and young that subsequently the surface was 

 occupied by a growth of marsh vegetation, and the bituminous coal was 

 formed without a trace of fishes. 



Mr. A. H. "Worthen also read a paper upon the occurrence of fish remains 

 in the carboniferous limestones of Illinois. The occurrence of these remains 

 has up to the present time been considered extremely rare in the mountain 

 limestones of the Western States ; and except in the thin bands of limestone 

 about to be described, they are among the rarest of the several beds that com- 

 pose the sub-carboniferous series of the region under consideration. Several 

 years since, while engaged in collecting the fossils of this formation near "War- 

 saw, 111., Mr. -"W. observed a thin band of gray crinoidal limestone, which con- 

 tained the palate bones of fish in considerable numbers, and subsequent 

 research has revealed two more of these " platforms of death " lower dowa in 

 the series, densely filled with these remains. The upper fish-bed is situate 

 in the upper part of what Mr. "W. calls, for want of a better name, the Lower 

 Archimedes Limestone, since it is the lowest bed at present known to contain 

 fossil corals of the genus Archimedipora. The remains from this bed, with one 

 or two exceptions, consist entirely of palate teeth, associated with cyathophylla- 

 forme corals, spirifer oralis and spirifer cuspidatus. The middle fish-bed is 

 situate at the base of this Archimedes limestone and near its junction with 

 the cherty beds below. This bed has proved by far the most prolific in these 

 remains, and from it Mr. "W. obtained more than five hundred well preserved 

 teeth in a single locality, and on a surface not exceeding ten feet square. The 

 fossils from this bed are mostly jaw teeth, with comparatively few palate teeth 

 and spines. The matrix in which they are imbedded is a coarsely granular 

 crinoidal limestone, not above four inches thick, and sometimes so friable as 

 to be easily crumbled between the fingers. This character of the matrix 

 enables the collector to obtain these delicate and beautiful fossils in a rare 

 state of preservation. Beside the cyathophylla-formed corals in the upper 

 bed, we have an interesting coralline form occurring in equal abundance and 

 belonging to a genus which he did not know. He also obtained the head of 

 one species of Actinocrinus from this stratum. This bed is separated from 

 the one above by the limestones and marlites of the Keokuk quarries, from 25 

 to 30 feet in thickness. The lower fish bed is situate near the top of the 

 Burlington and crinoidal limestone, and the stratum in which the fish remains 

 occur does not differ materially either in its lithological or paleontological 



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