REVIEWS. 



439 



Journal of the Geological Society.' In a subsequent visit, Dr. Dawson 

 obtained from another erect stump many additional remains of these smaller 

 reptiles, and, on careful comparison, was induced to refer them to three 

 species, all apparently generically allied, and for which he proposed the 

 name of Hylonomus or " forest- dweller." Hylonomus Lyelli was an ani- 

 mal of small size, of lacertian form, with large and stout hind limbs, capa- 

 ble of walking and running on dry land ; and though its vertebrae were 

 imperfectly ossified externally, yet their articulation was sufficiently firm 

 to have enabled the creature to erect itself on its hind limbs or to leap. 

 The ribs, long and much curved, imply a respiration of a higher character 

 than that of modern batrachians, and consequently a more vitalized mus- 

 cular system ; if to these structural points we add the somewhat rounded 

 skull, indicating a large brain, we have before us a creature which, how- 

 ever puzzling in its affinities when anatomically considered, is clearly not 

 to be ranked as low in the scale of creation as modern tailed batrachians, or 

 even as frogs and toads. The bony scales, moreover, with which it was 

 armed below, and the ornate apparatus of horny appendages with which it 

 was clad above, show that this little animal was not a squalid, slimy dweller 

 in mud, like Menobranchus and its allies, but rather abeautiful and sprightly 

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

 colouring with the insects it pursued and devoured." The remains of as 

 many as eight or ten individuals obtained from three erect Sigillarise is 

 an indication that these creatures were very abundant. Hylonomus acie- 

 dentatus was about twice as large as the species last described ; its habits 

 and food may have been similar, but its dental apparatus was stronger and 

 more formidable. Of Hylonomus Wymani no complete remains have been 

 found ; it was very diminutive, all the fragments met with being almost 

 microscopic in size. Its length could not have exceeded 4 or 5 inches, and 

 its form, was thin and slender. It might be questioned whether this little 

 creature was not the young of one of the other species, but so far a com- 

 parison does not favour such a view. 



"Hylonomus Wymani probably fed on insects and larvse, and searched for these among 

 the vegetable debris of the coal-swamps, which would afford to a little creature like this 

 abundant shelter. It occasionally fell a prey to its larger reptilian contemporaries ; for 

 quantities of its tiny bones occur in coprolitic masses, probably attributable to Dendrer- 

 peton. It is interesting to find reptilian life represented at this early period, not only 

 by large and formidable species, but by diminutive forms, comparable with the smallest 

 lizards and newts of the modern world. The fact is parallel with that of the occurrence 

 of several small mammalian species in the mesozoic beds. It will be still more signifi- 

 cant in this respect if the species of Hylonomus should be found to be truly lacertian 

 rather than batrachian." 



The Hylerpeton Dawsoni was found by Dr. Dawson in the laminated 

 material which fills the erect trees of the Joggins, the more distinctly sepa- 

 rable surfaces of which are often stained with ferruginous or coaly matter, 

 or fine clay, so that the fossils which occur on these surfaces are rendered 

 so obscure as readily to escape observation. The specimen on which this 

 species is established consisted of detached bones of a reptile scattered 

 over a surface so blurred and stained, that they escaped notice until most of 

 them were lost, and only fragments of the skull, a jawbone, and a few 

 other bones, were secured. On these fragments Professor Owen founded 

 the genus. 



" On the whole," says Dr. Dawson, " the Hylerpeton must have been generically dis- 

 tinct from the other reptiles found with it, and it is probable that it was of more aquatic 

 habits, swimming rather than walking ; and feeding principally on fish. More perfect 



