1863.] DAWSON — CARBONIFEROUS REPTILES. 473 



Six species of Reptiles or Batrachians have left their bones in the 

 repositories containing these remains of cuticle. Of these, Dendrer- 

 peton Acadianum was an animal too large to permit ns to suppose 

 that the integuments in question belonged to it. Hylonomus acie- 

 dentatus and Hylerpeton Dawsoni are each represented by a single 

 specimen only, and these do not occur on the same surfaces with the 

 remains of cuticle. Three species remain; and each of these is 

 represented by several individuals, whose remains occur near to the 

 fragments of cuticle, and whose size renders it possible that they 

 may have been its owners. Of these species Dendrerpeton Oweni 

 seems to have the best claim to the specimens described above as 

 Nos. 1 and 2, and probably also to No. 3. The specimens described as 

 Nos. 4 and 5 would then probably belong to Hylonomus Wymani and 

 H. Lyelli, the larger portion noticed as No. 4 to the trunk of the 

 latter, and that noticed as No. 5 to the trunk of the former. The 

 pointed appendages, referred to as No. 6, are not attached to any of the 

 larger fragments ; but their size and associations render it likely that 

 they belonged to Hylonomus Lyelli, and possibly to H. aciedentatus. 



I have ventured, in the work above mentioned, to give rough 

 restorations of the dermal coverings of these animals, according to 

 what I regard as the most probable arrangement of the parts ; but 

 such attempts must be regarded as merely provisional, and to be 

 corrected by future discoveries. I may add that I have no means 

 of determining the arrangement of the bony scales which these Rep- 

 tiles, or some of them, also possessed. These bony scales present, 

 under the microscope, a structure peculiarly similar to that of the 

 bones of Dendrerpeton and Hylonomus. They do not appear to be 

 attached to any of the portions of cuticle, and it is most probable 

 that they were placed on the head, neck, or abdomen, or perhaps 

 generally over the lower surface of the body, 



I have already expressed my belief that the species of Hylonomus 

 may have Lacertian affinities ; and I think their dermal coverings lend 

 some countenance to this view. We may, however, suppose them to 

 have been either true Reptiles having certain Batrachian tendencies, 

 or Batrachians presenting some structural points now limited to true 

 Reptiles ; or, lastly, we may suppose that the specimens entombed 

 in the erect Sigillarice may be the young of species of Reptiles too 

 large and vigorous, when adult, to be entrapped in such pitfalls. 



I would, however, observe that, in the case of Hylonomus, the 

 smooth cranial bones, the simple teeth, the long curved ribs, the 

 well-developed limbs, and the cutaneous appendages must absolutely 

 prevent this genus from entering either the Order Ganocephala or 

 the Order Labyrinihodontia, as denned by Owen. If they should 

 prove to be really Batrachian, a new Order must be constituted for 

 their reception, and its definition will present many points of coin- 

 cidence with those of the characters of the humbler tribes of Lizards. 



I propose, in the memoir already referred to, to figure and describe 

 all the characteristic bones of these creatures in my possession, with 

 the view of enabling naturalists to form more definite opinions on 

 these points. 



VOL. XIX. P4RT i, 2x 



