68 CATALOG OF FOSSIL FISHES IN THE MUSEUM 



To US, they appear too slender for Dinichthys, and rather like the 

 slender mandibles named by Newberry StenognathusP This genus 

 has recently been studied by HussakoP^ on the basis of a line speci- 

 men displaying most of the remains (including the dentition) of 

 an animal in a concretion from the Cleveland shale, preserved in 

 the British Museum. By the aid of this specimen it was shown that 

 the form named Dinichthys gouldi by Newberry, the incomplete 

 mandibles known as Dinichthys corrugatus and Stenognathus cor- 

 rugatus, and the complete mandible described by Claypole under 

 the name of Dinichthys gracilis, are all one form, to which Newberry's 

 generic term Stenognathus is applicable. This genus is especially 

 remarkable for its long, slender mandibles and its elongated postero- 

 superognathal. 



If we compare the mandibles of the "Buffalo specimeoi under dis- 

 cussion (E 2034), with those of Stenognathus, we see that they are of 

 the same type, thus proving that this specimen belongs in that genus. 

 Moreover, there is a correspondence in other plates which are dis- 

 tinctive for the genus, — for instance, the suborbital, which is roughly 

 triangular, rather than rectangular as in Dinichthys. For these rea- 

 sons it is clear that the specimen belongs in Stenognathus. 



The specimen was collected by Mr. F. K. Mixer from the Portage, 

 at Sturgeon Point, on the shore of Lake Erie, near Buffalo, N. Y. 



Stenognathus ringuebergi (Newberry) 

 (PL 15, fig. 2, PI. 69, fig. i) 



Dinichthys minor Ringuebesg, Amer. Joum. Sci., 3 ser., xxvii, p. 476. 1884. 

 Dinichthys ringuehergi Newberry, Pal. Fishes N. Amer., p. 60. 1889. 



This species has hitherto been known only by the type specimen, 

 a dorsomedian plate, in the collection of Mr. E. N. S. Ringueberg; 

 of Lockport, N. Y. We may now record a second specimen col- 

 lected by Mr. Bryant in the summer of 1916, which very materially 

 increases our knowledge of this form. 



Through the kindness of Mr. Ringueberg we have had the privilege 

 of studying and photographing the type plate, and we here give an 

 account of it in the light of present knowledge of this group. 



" Trans. N. Y. Acad. Set., xvi, 30, pi. xxiv, figs. 27-28, 1897. 



^ Hussakof, L.: Upper Devonian Arthrodira from Ohio in the British Museum (Natural His- 

 tory). Geol. Magazine, [5], viii, 126, pi. viii, fig. 5 and text-fig. 6, 1911. 



