282 THE OLDEST AIR-BREATHERS 



perhaps, the clothing of its lower or abdominal parts. But the 

 most remarkable and unexpected feature of this little creature 

 was the beautiful and ornate scaly covering of its back and 

 sides. Modern Batrachians are characteristically naked, and 

 though we know that some fossil species had coverings below  

 of bony scales, these seemed rather to ally them with bony 

 fishes. One of the specimens of Hylonomus had associated 

 with it a quantity of crumpled shining skin, black and car- 

 bonaceous, and which may perhaps have been tanned and so 

 preserved by the water filling the hollow tree impregnated 

 with solution of tannin from the bark. This skin was covered 

 with minute overlapping scales, which, under the microscope, 

 showed the structure of horn rather than of bone. Besides 

 these ordinary scales there were bony prominences, like 

 those of the horned frog, on the back and shoulders, and a 

 species of epaulettes made of long horny bristles curved down- 

 ward, and apparently placed at the edges of the shoulders. 

 Besides these there were in fnont and at the side rows of pen- 

 dants or lappets, all no doubt ornamented with colouring, 

 though now perfectly black. It may be asked what was the 

 use of the ornate covering, and perhaps the question raises 

 that perplexing problem, of the use of beauty in a world where 

 there were no animals with higher aesthetic faculties than those 

 of Batrachians. Scudder suggests a somewhat prosaic use in 

 supposing them to be an armour against the venomous scor- 

 pions which were the contemporaries of these little reptiles, 

 and some ot them almost as large in size. But the word " ven- 

 omous " raises another question, for we only infer that the 

 scorpions were venomous from modern analogy and traces of 

 an inflated joint at the end of the tail in some specimens. We 

 have no absolute certainty that the subtle and complex organic 

 poison of the scorpion, and his beautiful injection syringe for 

 placing it under the skin, were perfected at this early time. 

 Thus we have in the far back Carboniferous age a creature as 



