1192 ON SOME ADDITIONAL LABYRINTHODONT FOSSILS, N. S. WALES- 



integumentary scales overlie the vertebraB and ribs, while according 

 to Miall (Report 1873, p. 245) this armour is entirely ventral. 

 However (ib. p. 246), it is also stated that "granular, shagreen-like 

 scales have been found to cover other parts of the body of a few 

 Labyrinthodonts." If these scales are really ventral, the supposed 

 series of neural spines must be regarded as the representative of 

 the lower face of the notochord. In any case, however, the integu- 

 ment presents a finely granular surface, studded with small scutes, 

 which are arranged sometimes singly or by twos and threes, and 

 sometimes in broad patches. No sort of symmetry in the distribu- 

 tion of these patches is observable, or in their shape; so that one 

 is led to conjecture that these ' scutes ' appeared piecemeal with 

 advancing age, and may perhaps have disappeared in the same way. 

 The shape of those which are isolated, and therefore developed 

 without interference, is elliptical, the longer axis being transverse 

 to the spine ; the margin forms an elevated rim, which surrounds 

 a depressed area at apparently the same level as the skin outside. 

 When they are grouped in numbers they are either arranged along 

 diagonal lines like the scales of ganoids, the diagonals sloping 

 forwards and inwards, or they are set in quincunx, like shingles on 

 a roof, or scales in ordinary fish, but not overlapping, although a 

 striking resemblance to imbrication is produced by the irregular 

 development of the rim, the anterior portion being little raised, or 

 not at all, while the posterior is even more elevated than in the 

 isolated examples. They remind one forcibly of the dermal 

 papillae of Monacanthus, or of sharks. 



These two fossils seem sufficiently hard to allow of transparent 

 microscopic sections being prepared from them ; a method which 

 would throw much light upon doubtful and unknown points of 

 structure. 



