ON CLIMAXODUS AND JANASSA. 385 



merge into tJbat of Janassa. Ultimately, perhaps, Petalodus will 

 be found to be more closely related than can at present be de- 

 monstrated ; for it is not only in the Petalodontoid form that a 

 resemblance is observed, but likewise in the primary teeth them- 

 selves, which show a remarkable similarity in general form to 

 some of the Petalodontes. 



Professor M'Coy seems to think that his Climaxoclus imbri- 

 catus is related to PcBcilodus. The relationship, however, with 

 this genus seems to us to be remote, though it may have some 

 characters in common with Janassa. 



The bodies of these two fishes, Janassa and Climaxodus, were 

 covered with shagreen. In the former it is beautifully preserved, 

 the granules being highly polished, irregularly rounded, vpith 

 one side a little flattened and obtusely denticulated. On the 

 small slab, with numerous teeth of Climaxodus, already noticed, 

 is a great quantity of granular matter, but the granules are much 

 disturbed : a few however are well displayed, and show consi- 

 derable resemblance to those of Janassa, but the denticulations 

 at the side are produced into sharp points, and the surface is 

 undulated. 



Although Climaxodus lingumfonnis was pretty fully described 

 in the paper already referred to we will make, on the present 

 occasion, some general remarks on the teeth in our possession, 

 and also redescribe them. 



The species cannot be considered common, though we have 

 obtained eighteen primary teeth in the shale at Newsham and 

 elsewhere, and eight of the secondary or Petalodontoid form. 

 The largest of the former is Ifths of an inch in length, including 

 the root, and upwards of ^ths of an inch wide at the broadest 

 part. The smaller are not more than fths of an inch long, and 

 are oblique : these are the second primary teeth. There are 

 three about this size in the collection. We have one however 

 which, from its obliquity, is undoubtedly a lateral tooth, that is 

 only |ths of an inch in length. They are ovate, depressed, with 

 the broad extremity anterior. The crown is upwards of two- 

 thirds of the entii'c length, and is divided into two portions, 



