AQUATIC ANIMALS OF THE COAL. 



209 



the tail-joint of Slimonia (Pterygotus) acuminata. There are no 

 surface markings or marginal serrations." 



Locality. — Coal measures, Joggins, N.S. 



IV. Fishes. — Remains of fishes occur in connexion with eighteen 

 of the coal-beds at the Joggins, usually in the roof-shales, though 

 detached scales, teeth, spines, or coprolites, are of occasional though 

 rare occurence in the coal itself, especially where the latter passes into 

 coarse coal or carbonaceous shale. One thin bed, No. 6 of Division 4 

 of the Section, is full of remains of small fishes. It is hard and 

 laminated, and roofed with a calcareous bed full of remains of aquatic 

 animals. It has a true stigmarian underclay. I suppose it to have 

 been a swamp or forest submerged and occupied by fishes while its 

 vegetation was still standing. It contains remains of fishes of the 

 genera Ctenoptychius, Diplodus, Bhizodus, and Palatoniscus. It also 

 contains Cythere, Naiadites, and Spirorbis. In the other beds which 

 contain fish-remains, most of these consist of small Lepidoganoids, but 

 there are occasional teeth and scales of large species of Bhizodus, and 

 also teeth of Selachian fishes of considerable size. 



Among these I have in my collection a tooth of a Ctenoptychius 

 (Fig. 52), differing from any species of which I have seen a description. 



Fig. 52. — Tooth of Ctenoptychius cristatus, N.S. ; nat. size and magnified. 



It is two lines in length, with fourteen sharp denticles, much compressed, 

 and with a narrow base. Another very fine tooth found in these beds 

 appears to belong to M'Coy's genus Conchodus (Fig. 53). It has seven 



Fig. 53.— Tooth of Conchodus plicatus, N.S. Fig. 54 — looth of Psammodus. 



strong angular ridges, with a slightly granulated and obliquely wrinkled 



