"Six species of reptiles have left their bones in the repositories containing these remnants of cuticle. Of these, _Dendrerpeton acadianum_, was an animal of too great size to have been clothed with integument of this character and of such dimensions. Hylonomus aciedentatus and _Hylerpeton dawsoni_ are each represented by only a single specimen, and these did not occur in proximity to any of the portions of cuticle, except that the appendages were found near a specimen of the former. Of the three remaining species, _Dendrerpeton oweni_, from its size, the number of specimens found, and the juxtaposition of their bones to the fragments of cuticle, appears to have the best claim to the integument included under Nos. 1, 2, and 3; and in this case, while the creature had its throat, and perhaps its abdomen, armed with bony scales, its upper parts and tail, as well as its limbs, had a uniform covering of small, thin imbricated horny scales, in the manner of many modern reptiles. "If the remaining portions of integument, Nos. 4 and 5, as would seem likely, belonged to two species, both of smaller dimensions, there would seem little reason to doubt that these were _Hylonomus lyelli_ and _H. wymani_. In this case, both of these species must have possessed a highly ornate covering of horny scales and appendages, comparable with that of many of the modern lizards, while there seems good reason to believe, as stated in a previous paper, that they were in part protected by bony scales somewhat like those of _Dendrerpeton_. These points, however, we shall consider more in detail under the sections which refer to the species of _Hylonomus_.