Correspondence — Mr. T. P. Barkas. 381 



walls of buildings, or from quarries, where the commencement of 

 atmospheric action can be traced. 



Manchester, Z\st May, 1869. D- MACKINTOSH. 



TEETH OF GLIMAXOBUS, FROM THE COAL MEASURES. 



Sir, — I again venture to trouble you with a few remarks on the 

 rare Coal-measure fish Climaxodus, about which, so far as I have 

 been able to ascertain, nothing whatever is known beyond the fact 

 of its having possessed teeth of a very peculiar form. 



On page 496 of the Geological Magazine (November, 1868), 

 there appears a figure of the first specimen of Climaxodus discovered 

 by me in the shale of Newsham Colliery, Northumberland, and at 

 page 42 (January, 1869), reference is made to three additional 

 specimens from the same Colliery. Since those communications ap- 

 peared I have found four specimens of Climaxodus, three of which 

 closely resemble the figure just referred to, but one appears suffi- 

 ciently destinctive in its form to justify its being erected into a new 

 species. In size it very closely resembles that which I named 

 Climaxodus ovatus, but in its general outline, and especially in the 

 ridges which traverse its surface, it is remarkably unlike any speci- 

 men I have previously found or examined. I propose for it the 

 specific name vermiformis, as descriptive of its leading peculiarity, 

 viz. the possession of vermiform ridges across its surface. Climax- 

 odus vermiformis, is from the Low Main Coal Shale, Newsham 

 Colliery, Northumberland. 



General character : Tooth longer than wide, gradually narrowing 

 towards the posterior extremity, the crown crossed by vermiform, 

 irregularly bent, transverse ridges at right angles to its length ; the 

 surface somewhat rough and granular. 



Climaxodus vermiformis, sp. nov. The specimen is nearly perfect, 

 a fragment of the posterior extremity being absent ; the length of 

 the specimen is six-eighths of an inch, the width at the broadest 

 part is also six-eighths, and the narrow posterior end is four-eighths 

 of an inch wide ; the crown is crossed by three very irregular ver- 

 miform ridges, the second ridge being excessively bent, at one part 

 of its course it approaches the first ridge within one-sixteenth of an 

 inch, and at another part it is four-sixteenths of an inch from it ; the 

 third ridge is imperfect, but the portion that remains indicates that 

 it also crossed the crown of the tooth in a tortuous manner, the 

 crests of the ridges on the crown of the tooth are nearly on the same 

 level, and the spaces between each ridge are deeply concave; the 

 surface of the bone forming the tooth, when seen by means of a 

 microscope, presents a shimmering lustre, although the tooth, 

 when examined by the naked eye, appears perfectly black. The 

 tooth is attached to a thin plate of bone, and the curve of the 

 plate supporting the tooth is sigmoidal and resembles that of Cli- 

 maxodus ovatus, a specimen of which may seen in the British 

 Museum by anj^one who is desirous of an acquaintance with the 

 teeth of this obscure Carboniferous fish. T. P. Barkas. 



Newcastle-on-Tyne, June 11th, 1869. 



