FOSSIL FISHES. 615 



are composed. The structure of those parts enabled them to resist the 

 severe usage to which they must have been subjected. 



The enormous teeth of Gorgonichthys constitute the most formida- 

 ble dentition known in the animal kingdom, unless possible exception be 

 made in favor of the great Eocene shark, Carcharodon. 



Coccosteus Cuyahoga, sp. n. 



A single plate was described by Dr. Newberry in the second volume 

 of the Palaeontology of Ohio (p. 32), which so closely resembled the dorso- 

 median plate of Coccosteus both in form and in ornamentation, that it was 

 named C. occidentals. This, if rightly named, was the first specimen of 

 the genus from North American strata, all previously described having 

 come from Europe. In the first volume of the same work Dr. N. had 

 figured a small jaw under the name of Liognathus spatula us, and sug- 

 gested that it belonged to the same fish or was at least Coccostean. The 

 specimen is very imperfect and it is impossible to feel certain of the refer- x 

 ence. If it really belongs to this genus it differs considerably from all 

 the other known mandibles. 



Both these fossils came from the Corniferous limestone at Delaware 

 and belong consequently to the lower part of the Devonian strata. 



Since the publication of Dr. Newberry's report, Mr. Whiteaves, of the 

 Canadian Survey, has published the ^description of a Coccosteus (C. Aca- 

 dicus), from the lower Devonian beds of Campbelltown, N. B., whereby 

 the geographical range of the genus is extended to the Atlantic coast in 

 the northeast. 



Coccosteus does not occur in the lowest or flagstone beds of Scotland 

 and is not found until the middle strata are reached. In Acadia it is 

 associated with Cephalaspis, a fossil characteristic of the lowest Scottish 

 Devonian. Conditions probably had much to do with this distribution 

 but the evidence of the vertebrates seems to point to a conclusion that 

 the Corniferous of Ohio does not exactly correspond to the lowest Devon- 

 ian ot Europe, but rather to the overlying strata there classed as middle 

 Devonian. The complete absence, so far as yet known, of all Cephalaspid- 

 ian and Pteraspidian fossils bears strongly in the same direction espe- 

 cially as we now know that fishes of this order existed in N ew Brunswick 

 in early Devonian and in Pennsylvania in late Silurian times. 



The recent discovery by Dr. Clark of a Coccosteus in the Cleveland 

 shale enables us to add another species to the American list and to carry 

 the upper limit of its generic range almost to the top of the Devonian 

 system. 



The new species is much larger than any previously reported. The 

 largest of the Scottish species (C. decipiens) measures only*sixteen inches 

 * Illustrations of the Fossil Fishes of the Devonian rocks of Canada, 1881. 



