284 THE OLDEST AIR-BREATHERS 



ratus of horny appendages, with which it was clad above. 

 These last, as described in the last section, show that this little 

 animal was not a squalid, slimy dweller in mud, like Meno- 

 branchus and its allies, but rather a beautiful and sprightly 

 tenant of the coal-formation thickets, vying in brilliancy, and 

 perhaps in colouring, with the insects which it pursued and 

 devoured. Remains of as many as eight or ten individuals 

 have been obtained from three erect Sigillarise, indicating that 

 these creatures were quite abundant, as well as active and ter- 

 restrial in their mode of life. 



With respect to the affinities of this species, I think it is 

 abundantly manifest that it presents no close relationship with 

 any reptile hitherto discovered in the Carboniferous system, 

 except perhaps some of the smaller forms in the Permian of 

 Europe, with which Credner and Fritsch have compared it. It 

 is scarcely necessary to say that the characters above described 

 entirely remove this animal from the Labyrinthodonts. Equal 

 difficulties attend the attempt to place it in any other group 

 of recent or extinct Batrachians or proper reptiles. The struc- 

 tures of the skull, and of some points in the vertebrae, certainly 

 resemble those of Batrachians ; but, on the other hand, the 

 well-developed ribs, evidently adapted to enlarge the chest in 

 respiration, the pelvis, and the cutaneous covering, are un- 

 exampled in modern Batrachians, and assimilate the creature 

 to the true lizards. I have already, in my original description 

 of the animal in 1859, expressed my belief that Hylonomus 

 may have had lacertian affinities, but I do not desire to speak 

 too positively in this matter ; * and thall content myself with 

 stating the following alternatives as to the probable relations 

 of these animals, (i) They may have been true reptiles of low 

 type, and with batrachian tendencies. (2) They may have 

 been representatives of a new family of Batrachians, exhibit- 

 ing in some points lacertian affinities. (3) They may have 



1 I am glad to say that Fritsch and Credner now lean to the same view. 



