[Paoc. Roy. Sec. Victoria 28 (N.8.), Part II., 1916.1 



Art. XIV. — On the Generic Position, of " Astevolepis ornata, 

 var. australis" McCoy: with Description of a New 

 Variety. 



By FREDERICK CHAPMAN, A.L.S , &c. 

 (Palaeontologist to the National Museum, Melbourne.) 



(With Plates XX. and XXI.). 



[Read October 14th, 1915]. 



Introductory Note. 



The holotype of the above species and another specimen, practi- 

 cally a surface impression, were the only known examples when McCoy 

 published his description in 1876. 1 Since then W. H. Ferguson, of 

 the Geological Survey of Victoria, discovered a cranial shield at 

 the same locality, Buchan, in Gippsland. This latter specimen 

 1 showed to Mr. D. M. S. Watson during his visit to .Melbourne with 

 the British Association last year, and lie concurred with me in the 

 view that the fish showed coccostean affinities. Comparison has also 

 been made with some good examples in the National Museum of 

 the Canadian species of Phlyctaenaspis, the genus to which I refer 

 this Devonian fish. 



Original Description. — The following is McCoy's description of 

 the holotype. " Plates of body covered with close stellated tuber- 

 culations ; tubercles rounded, sub-equal, smooth, each with about 

 12 short radiating ridges nearly equally spaced round its base, 

 irregularly placed, averaging less than their diameter apart, rarely 

 arranged more closely in lines, and rarely anastomosing into short 

 vermicular ridges. Average number of tubercles, 5 in 3 lines. 

 Interstices between the tubercles, granulo-punctate. Thickness of 

 plates about '2 lines." 



Neither the presence or disposition of sutures and sensory canals 

 were mentioned by McCoy, although traces of the latter are well 

 marked in the holotype and accompanying specimen. The feature 

 of the stellate tubercular ornament of the dermal armour seems 

 alone to have been relied upon for determinative purposes. This 

 form of ornament of the dermal shield is, however, found both in 

 the Asterolepidae and the Coccosteidae ; hence the discovery of a 

 more perfect specimen from Buchan showing the coccostean 



1 Prod. Pal. Victoria, dec. i\\, p. 19, pi. xxxv, %». 7. 7r<, ~J>. [Figure reversed]. 



