The Primitive Fishes 275 



Hind then adds "this is most valuable evidence, as beds 

 of coal and ironstone occur in the Carboniferous Limestone 

 series of Scotland, where there is a frequent alternation 

 of beds, with a typically marine fauna, with those containing 

 Carbonicola and its congeners." 



The question then arises: Is there direct evidence of 

 the existence of elasmobranch fishes in marine Carboni- 

 ferous strata? As partial evidence of the complete absence, 

 from some records, of fish remains in certain typical marine 

 beds, the writer might cite Vaughan's paper entitled "The 

 Palaeontological sequence in the Carboniferous Limestone 

 of the Bristol area" (205: 181). Here the author gives 

 alike the exact succession of beds, and elaborate lists of 

 the fossils characteristic of each. He at the same time 

 quotes Lloyd Morgan's series of papers on the subject. 

 Not a fish is recorded from any of the beds examined. 

 Abundant evidence of a like nature could be furnished. 



But that frequent oscillations were proceeding in the 

 earth's crust, is evidenced by the careful record of Stobbs 

 on "The Marine Beds in the Coal Measures of North 

 Staffordshire" (702:495). He cites at least six narrow 

 and typical marine bands intercalated between an extensive 

 set of beds that are all of freshwater origin. And it is 

 usually in freshwater ironstone or in shaley coal beds that 

 fish remains, and frequently also plants, occur. He then 

 refers to dark shale that contains large "bullions" which 

 were flattened in shape, and were very fossiliferous. These 

 bullions enclosed Pterinopecten papyraceus, Dimorpho- 

 ceros gilbertsoni, Glyphioceras diadema, Lis tr acanthus 

 wardi, and Acanthodes wardi. Now the latter is a fish 

 that invariably is reported with freshwater crustaceans, 

 ganoids, plant remains etc. But Hind in the latter part 

 of Stobb's paper says that "Listracanthus is associated with 

 a marine fauna," and later (p. 529) gives a list of fourteen 

 freshwater fish remains from these bullions of the supposed 

 marine bed. We would suggest that the bullions are second- 

 ary inclusions from a freshwater bed deposited alongside 

 marine organisms. 



As bearing on the above questions, as well as on the 

 group of fishes already studied, and others to be studied in 



