78 MR. J. W. KIEKBY ON PERMIAN PISH AND PLANTS. 



The overlap of the scales is considerable ; their articulation is 

 assisted also as in other Palceonisci, &c, by teeth that project 

 from the dorsal margin, and fit into sockets on the reverse of the 

 ventral portion of the scales. In advance of each lobe of the 

 caudal fin, and of the anal and dorsal, are placed four or five large 

 scales, which are altogether different in form from the scales of 

 the flank. They graduate from ovate or bluntly pointed scales 

 to such as are lanceolate ; and those of the latter form pass by . 

 insensible modifications into the fulcral scales or rays of the fin- 

 borders. 



There is more than one species to which this Palceoniscus has 

 some resemblance ; P. VoUzii, P. fultus, P. angustus, and P. 

 Vratislaviensis, for instance, all appear related, though appar- 

 ently distinct, forms. Perhaps the fish that this species most 

 nearly resembles is Palceoniscus gla/phyrus, Ag., of the Marl-slate. 

 It resembles it in size, largeness of scales, smallness of gape, size 

 of orbit, and in position and structure of fins ; but it differs from 

 it in having a comparatively larger head — the head of P. glaphy- 

 rus being only one-fifth of the entire length, whereas that of P. 

 vwrians reaches one-third — and in having a large operculum, 

 scales that vary more in size, and in having them with plain 

 margins, while P. glaphyrus has them deeply serrated. P. gla- 

 phyrus, moreover, does not appear to have possessed the large 

 notched scales that mark the lateral line in P. v avians. With 

 these differences before me, I have not hesitated to describe the 

 present form as a distinct species. 



P. varians has occurred in the laminated marls at the base of 

 the Upper Limestone, in the strata immediately underlying the 

 fish-bed, in the Dun Stone, and in the Main or Honeycomb Stone 

 in the New Quarry at Fulwell ; also in the fish-bed in the Old 

 Quarry, Fulwell. And the fragment of a fish that I met with in 

 the laminated limestone of Marsden apparently belongs to this 

 species. 



Pal^onisctjs Abbsii, Kirliby. PL IX, figs. 3a, 31. 

 Annals of Nat. Hist., 3rd Series, vol. IX, p. 268. 

 Length from snout to end of caudal fin rather more than 4 



