71 
DESCRIPTION OF TIIE SPECIES. 
I— ANIMALIA. 
1.— Pisces. 
Remains of fossil flsli are here only of interest, as they occur with the 
fossil plants in the coal heels. In the lower series there is only one species 
quoted by Prof, de Koninck, i.e., Tomodns convexus Agass. (?), from the 
Carboniferous Marine Series at Tillegharry, New South Wales. 
The fish which concern us here occur in the Newcastle beds (Upper 
Coal Measures) and in the Ilawkesbury-Wianamatta beds. The most inter- 
esting point about them is that they are, partly at least, distinctly hetero- 
cereal. Prom the Newcastle beds one species is known, and here the 
occurrence of a heterocercal fish is quite natural, because, as we have seen, 
these beds most probably represent the Permian Epoch. 
Prom the Ilawkesbury-Wianamatta beds three species are known — ■ 
one at least certainly, the others probably, heterocercal, and these occur in 
beds, which, from their position, have to be considered as Mesozoic. In the 
same beds there also occur Labyrinthodont remains of distinctly Mesozoic 
habit, and we have thus a clear case of heterocercal fishes surviving into 
Mesozoic (Triassic and Jurassic) strata, although the same fish tvere formerly 
quoted as proving the Palaeozoic age of the strata (Ilawkesbury-Wianamatta 
beds) in which they occur. We now know that these fish do not decide the 
age of the strata, but they have to he considered of the age attributed to the 
beds from their geological position. 
The figures of the three species from the Ilawkesbury-Wianamatta 
arc copied from photographs which the late Rev. W. B. Clarke had kindly 
sent me some years ago ; and the tail of Urosthenes is copied from Dana’s 
work. I shall introduce the fish in the same manner as they were originally 
described, because it is not easy from photographs to make any further 
comparisons. The fish to be mentioned here all belong to the class Ganoidci. 
