BUFFALO SOCIETY OF NATURAL SCIENCES 163 



to Agassiz's genus Cladacanthus." For comparison, an 

 outline figure of the type of Cyrtacanthus dentatus (fig. 55, 

 B) is given side by side with that of the present specimen. 



The Buffalo specimen undoubtedly has a resemblance to New- 

 berry's type, but it cannot be unreservedly regarded as of that species. 

 The denticles on the incurved margin are, absent, although one or two 

 blunt protuberances suggest weathered denticles; and the outer sur- 

 face near the distal extremity is not ornamented with tubercles as in 

 the type. But on the whole the spine is more like the distal end of the 

 type of C. dentatus than any other ichthyodorulite, and it is best to 

 leave it in that species as was done by Newberry. Additional material 

 illustrating the species is much to be desired. 



As regards the aflSnities of Cyrtacanthus: it represents either a head 

 spine, as stated above, or an unpaired spine placed in the median line 

 of the fish. Newberry thought, as expressed in his note on the label 

 of the Buffalo specimen, that Cyrtacanchus is probably one arm of the 

 spine known as Cladacanthus. If we bear in mind that Cladacanthus 

 is a synonym for Erismacanthus, this opinion is about all that one 

 may express even at the present time; for Cyrtacanthus undoubtedly 

 belongs in the group of head or median spines which includes Eris- 

 macanthus, Harpacanthus and allied forms. 



Edestus minor Newberry 



£ 2153 Cast of a series of six teeth, attached to their supporting 

 element. 



Coal Measures: Indiana. (History of specimen un- 

 known.) 



Genus Gamphacanthus S. A. Miller^" 



Heteracanthus. J. S. Newberry, Paleoz. Fishes N.Amer., 66, 1889, [preoccupied]. 

 Gamphacanthus, S. A. Miller, First Appendix [to N. Amer. Geol. and Pal.] 

 715, 1892. 



'5 In a paper published after the above was already in the hands of the printers, Eastman (Proc 

 U. S. Nat. Mus., vol. 52, p. 244, igi?) employs the name Heteracanthus for Gamphacanthus. There 

 seems to us no valid reason for doing so. Heteracanthus is clearly preoccupied. This was shown 

 as long ago as 1892, by S. A. Millei, who proposed Gamphacanthus to replace it, which name,wa 

 accepted by 0. P. Hay in his Bibl. and Cat. Fos. Vert. N. Amer., 1902 (p. 332). The fact thatt h 

 relationship of these spines is at present unknown and they must be placed under the head of Ich 

 thyodonilites, does not affect the matter of the name. If a generic name is applied it is amenable 

 to the rule of priority. 



We note also that Eastman refers these spines to Chimasroids^on the groimd of their occurrence 

 in the same formation with Ptyctodonts (which latter he considers to be Chimsroids). Unfortu- 

 nately for this view, there are no fin-spines, nor indeed any skeletal or dermal elements similar to 

 the Gamphacanthus spines in any Chimaeroid. 



