NOTES ON DEA'ONIC FISHES FRQM SCAUMENAC BAY, 



QUEBEC 



BY L. HUSSAKOF 



I An almost complete specimen of Coccosteus 



Up to the present time Coccosteus has been known in America 

 only from fragmentary remains. No specimen has been found 

 showing the head with its associated armor plates, or with 

 the notochord and dorsal fin. It is therefore of great interest 

 to record the discovery recently of an almost complete specimen 

 of Coccosteus canadensis — a species described 

 by Dr A. S. Woodward,^ in 1892, from a cranium. The 

 specimen was collected for the New York State Aluseum, from 

 the Upper Devonic shales on the shore of Scaumenac bay, near the 

 village of Migouasha, Quebec. It came from a layer of .thin-bedded 

 shale at a level considerably below the massive, fine-grained sand- 

 stone containing the exquisitely preserved ferns made known by 

 J. W. Dawson, and the splendid specimens of Bothriolepis with the 

 soft structures and fins, described by Patten. The specimen was 

 contained in a small slab of shale which had weathered out so that 

 its upper surface lay exposed. 



Description of specimen. The specimen consists of the head, 

 a portion of the dorsal armor, several ventral plates, the im- 

 pression of the notochordal region, some neural spines, and part 

 of the dorsal fin. From its orientation on the slab, the 

 animal appears to have become turned ventral side up after 

 death, and to have settled into the sediment in that position. The 

 head and dorsal armor were thus embedded in natural association, 

 while the ventral plates, on the softer tissues loosening up, either had 

 drifted out of their places (this is the case with the three plates seen 

 in figure i to the right of the median axis of the specimen) ; or had 

 fallen onto the dorso-median plate partly covering it. In collecting 

 the fossil, the slab was unfortunately opened in such manner that 

 most of the actual bone was lost and only the impressions (of the 

 dorsal tuberculated surface) are shown in the rock. 



Head. The head (CRAN) is ii)<2 centimeters long and shows, as 

 Impressions, most of the sutures and lateral lines. As it has already 

 been well described by Woodward it is unnecessary to refer to it 

 again in detail. To the left of the head is seen the right suborbital 



^ A. S. Woodward. Further Contributions to Knowledge of the Devonian 

 Fish-fauna of Canada. Geol. Mag., N. S., Dec. 3, 1892, IX, p. 481-85, pi. xiii. 



127 



