NOTE ON AN UNDESCRIBED FOSSIL FISH. 199 



V. — Note on an undescribed Fossil Fish from the Newsham Coal- 

 Shale, near Newcastle-on-Tyne. By Albany Hancock, F.L.S., 

 and Thomas Atthey. 



For several years past we have been much puzzled with a large 

 ichthyic tooth that is not by any means uncommon at Newsham. 

 We could not make out to what fish to assign it. Indeed there 

 is but one, of sufficient size, found in the locality, of which the 

 teeth are not known, that was at all likely ; and the remains of 

 this were supposed to belong to Rhizodus ; and as the teeth in 

 question are perfectly devoid of cutting-edges, they could not 

 belong to it. We had doubts, however, as to these remains 

 really being those of that obscure fossil, and thought that pro- 

 bably they would be found some day or other associated with 

 our unknown tooth — that it belonged, in fact, to these supposed 

 Rhizodus-bones. And such is apparently the case. 



A jaw has just been obtained at Newsham with one of these 

 large enigmatical teeth attached, and the surface-ornament of 

 the bone is of the same character as that of the remains alluded 

 to. This jaw, which is a left ramus, is quite perfect in front ; 

 but the proximal extremity is broken away. The part that re- 

 mains is upwards of seven inches long, and an inch and five- 

 eighths wide ; the margins are nearly parallel ; the alveolar 

 border is pretty straight, but rises up a little in front, which 

 is rounded. About an inch behind the anterior extremity, a 

 large stout laniary tooth is placed on this elevated part ; it is 

 slightly recurved, but the apex is gone. What remains mea- 

 sures an inch in length; the base is broad, being quite five- 

 eighths of an inch wide ; and the upper, broken extremity is 

 three-eighths of an inch across. When perfect, this tooth could 

 not be less than an inch and five-eighths in length, as is proved 

 by comparing it with a perfect tooth of the same size at the base. 

 The base is deeply folded, the folds being rounded and covered 

 with minute, sharp, raised striae, which pass upwards and die 

 gradually out as they approach the broken extremity. 



Along the alveolar border there are nine small teeth, three- 

 eighths of an inch long; they have much the character of the 



