2 Evolution and Distribution of Fishes 



Throughout all of these strata, with the exception only 

 of the Carboniferous Limestone series, abundant fossil 

 plant remains often occurred side by side with entire fossil 

 fishes, or with their jaws, teeth, scales and spines. Such 

 remains again were at times associated with a stippled 

 and shining body that on reference to the skilled palae- 

 ontologist Traquair was identified as part of a carbon- 

 iferous eurypterid. Occasional thin beds of what were 

 identified as freshwater carboniferous molluscs at times 

 interrupted the plant and fish bearing strata, while the 

 now celebrated freshwater limestones of Burdie House, and 

 of Camps near Mid Calder, revealed remains of ferns, 

 lepidodendra, calamites, and fishes, surrounded by myriads 

 of freshwater entomostracans, mainly Leperditia scoto- 

 burdiegalensis. 



Here then seemed to be an enormous accumulation of 

 non-marine strata, that at times was constituted in places by 

 beds of coal from one or two inches to five feet in thick- 

 ness. In striking contrast to all of this were the rocks 

 and enclosed fossils that made up the main masses of the 

 Carboniferous Limestone system, on top of which the 

 writer was born and lived through his preuniversity years. 

 These often literally teemed with a complex of fossils that 

 proclaimed a very different and a typically marine life. 

 Broken remains of Productus, Spirifer, Encrinus, Euom- 

 phalus, and other equally characteristic marine organisms 

 at times almost made up the limestone basis in which the 

 more entire calcareous tests were imbedded. But amongst 

 all of these marine beds, over wide miles of country 

 studied, the writer only rarely found a genuine fish remain. 



More arresting and puzzling still, according to the then 

 accepted views, was the occasional Interbedding amongst 

 the Carboniferous Limestone rocks of an ironstone stratum 

 that enclosed just such plants, fishes and eurypterlds as 

 characterized the Calclferous rocks below. Their fossil- 

 ized remains usually occurred In ironstone or In ferruginous 

 shale, that Indicated chemical interaction between organ- 

 Isms and dissolved Iron salts, the latter of which had pre- 

 cipitated from the surrounding waters. With glee Tra- 

 quair at times welcomed such fish specimens when brought 



