16 CATALOG OF FOSSIL FISHES IN THE MUSEUM 



Several interesting conclusions may be drawn from this list as 

 well as from considerations of the character of the Conodont layer 

 itself. 



1. In the first place, we have here one of the most remarkable 

 assemblages of fossil fishes known from any Devonic formation. It 

 includes no less than 27 genera (not counting two or three^ too frag- 

 mentary for identification) with about 40 species. It is therefore 

 nearly as rich in species as the faunai of the Cleveland shale of Ohio, 

 although the specimens are, of course, not to be compared with the 

 latter in point of preservation. The fauna will also stand compari- 

 son in richness with any of the local facies of the Old Red Sandstone 

 of Scotland, such as the Achanarras, the Orkney, or the Cromarty 

 faunas; or with the remarkable fish faiuia made known ten years 

 ago by Jaekel, from the Upper bevonic at Wildungen, Germany.^ 



Apart from the large number of genera and species represented, 

 the Conodont-bed fauna is remarkable for the presence of so many 

 different groups. Nearly every , division of fishes that existed in 

 Upper Devonic times is represented — Sharks (all four divisions: 

 Pleuropterygii, Ichthyotomi, Acatithodia and Euselachia); Arthro- 

 dira, Ptyctodontidae, Ichthyodorulites, Dipneusti, Crossopterygii and 

 Acanthopterygii . 



2. Another remarkable feature about the Conodont fauna, is the 

 large number of forms peculiar to it. Out of a total of 34 identifi- 

 able species, 15 are known only from this formation; the remaining 

 19 are represented by groups of fours, fives, or less, in several dif- 

 ferent formations. The latter species are mostly such as had a long 

 geological history, some of them ranging through several successive 

 formations, or had a very wide geographical distribution. 



The following table shows the range of the fossil fishes common to 

 the Conodont bed and other formations. As will be seen from this, 

 4 species are common to the Conodont bed and the New Albany 

 shale. This is not surprising when we consider that both form- 

 ations are of Genesee age. It may also be noted that the mode of 

 preservation of the fossils and the character of the matrix of the 

 New Albany shale is, in certain areas at least, similar to those of 

 the Conodont bed. But it is surprising to find 6 species surviving 

 from the Hamilton. 



* For instance, the Aqauthodian represented by a fin-spine, and the extraordinary plates orna- 

 mented with broad parallel ridges, illustrated in figure 37, page 106. 



^O. Jaekel: Neue Wirbeltierfunde aus dem Devon von Wildungen. Sitzunsb. Gesell. NaturJ. 

 Freunde, Berlin, 1906, 73-85, with 10 figures. 



