ON OLIMAXODUS AND JANASSA. 333 



distinguished by having only five sides. Thus it appears that 

 each transverse row is composed of seven teeth, five of which 

 may be looked upon as primary, two as secondary, arranged 

 exactly as the teeth are in Janassa, and agreeing with them ex- 

 actly in number. 



Now it cannot be doubted that the disposition of the teeth is 

 the same in Climaccodus as it is in Janassa ; and in fact the speci- 

 mens of the former, on the slab previously mentioned, verify 

 this assertion when aided by the light dei'ived from the latter. 

 Alone perhaps these specimens might have justified the infer- 

 ence ; but taken in connexion with what is known respecting 

 Janassa, there can now be no hesitation upon the subject. Indeed 

 the large symmetrical, central teeth of two rows lie in proper 

 order one over the other ; and in contact with the upper one, 

 and side by side with it, is the first lateral tooth in its exact true 

 position ; and a little further away, but almost touching it, is a 

 secondary tooth, apparently belonging to this side. Overlying 

 the first, lateral, primary tooth in front are the distorted remains 

 of what seems to be the second lateral tooth. On the other side 

 of the central tooth, and some little distance from it, is another 

 primary tooth, which, from its oblique form, is undoubtedly the 

 second lateral tooth of this side : it lies in juxtaposition to its 

 flanking Petalodontoid tooth. All these teeth, with the excep- 

 tion of that last named, lie with their crowns uppermost, and 

 belong to one row ; the central tooth and the three lateral teeth 

 of one side are all present, and lie nearly in their natural order ; 

 and the second lateral tooth and the secondary tooth of the other 

 side are not far removed from their right position. So here we 

 see a whole row of seven teeth complete, with the exception of 

 one of the first lateral teeth. Two other small lateral teeth are 

 on the same slab, and rest with theii' faces downwards, or in the 

 opposite direction to those already spoken of. These belong 

 apparently to the opposing jaw, and both lie in contact with the 

 large central teeth ; and one of them, as an opposing tooth, occu- 

 pies its correct position by the side of the upper central tooth. 

 A third Petalodontoid tooth lies a little apart, and probably be- 

 longs to this jaw. 



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