TRIASSIC LABYRINTHODONS. 195, 



I subsequently found that a fossil from Warwickshire Trias, figured in Plate 

 XXVIII, fig. 9, of the above-cited paper by Murchison and Strickland, was a 

 terminal phalanx showing a Batrachian character in the absence of the usual 

 modification for the insertion or attachment of a claw. 



Labyi'inthodon (Anisopus) scutulatus, Owen. 



Returning to the group of bones in Plate 6, figs. 1 — 5, I found them to belong 

 to a small reptile with the biconcave system of vertebrae, but which, from the 

 length, structure, and form of the long bones of the extremities, must have been 

 of terrestrial rather than marine habits, and which had the skin defended by 

 numerous small rhomboidal bony scutes, with a smooth central surface, and with 

 the outer surface sculptured by three or four longitudinal ridges (fig. 6). This 

 reptile had the hind legs twice as long and as strong as the fore. The humerus 

 (fig. l,k) is convex at the proximal extremity, it is expanded both at this and the 

 distal extremities, and is contracted in the middle. There is a portion of a some- 

 what shorter and flatter bone, bent at a subacute angle with the distal extremity 

 of the humerus, and which presents the nearest resemblance to the anchylosed 

 radius and ulna of the frog. The proximal extremity is wanting in the femur 

 (fig. 1,/), the remnant of the shaft is slightly bent, and is subtrihedral ; its walls 

 are thin and compact, and include a large medullary cavity. Both tibise exhibit 

 that remarkable compression of the distal portion of the shaft which characterises 

 the corresponding bone in the anourous Batrachia, and both likewise exhibit the 

 longitudinal impression along the middle of the flattened surface. 



The vertebrae (figs. 2, 4, and 3 magnified) are biconcave, with these surfaces 

 sloping obliquely from the axis of the body, as in the dorsals of a frog, indicative 

 of habitual curvature of the part of the spine formed by them. The aquatic 

 Salamanders, including the gigantic species from Japan, have both ends of the 

 vertebral body concave, but more conical than hemispherical, as in the present 

 fossil, which in this respect resembles the Labyrinthodont vertebrse (figs. 1 and 7) 

 in Plate 5. Portions of ribs associated with the above-described fossils showed 

 them to be longer and more curved than in t]>e existing remnants of the 

 Batrachian type. 



The Leamington fossil also exhibits a character, in the small, bony dermal 

 sculptured plates, not yet found in the Warwick or Wirtemberg Labyrinthodons, 

 which seems to remove it from all Batrachia— the naked reptiles, as they are 

 emphatically termed — and to approximate it to the Loricated Order. These 

 scutes (fig. 5) form a suggestive instance of the Crocodilian affinities of 

 the Leamington Batrachian ; we have already seen the same affinities mani- 



