Breger — Eodevonaria, a new Subgenus of Chonetes. 535 



group of Ohio, Indiana, New Jersey, New York and Maine. 

 Some specimens in the U. S. Geological Survey collections 

 from Little Brasna Lake, Somerest County, Maine, represent 

 the same type of the species as occurs in New Jersey, and 

 show very prominently the crenulated hinge line. 



2. Chonetes (Eodevonaria) dilatatus. — This characteristic 

 Lower Devonian fossil of the Continent occurs throughout 

 the middle and upper Eo-Devonian, and a few specimens con- 

 tinue into the Middle Devonian. Its greatest development is 

 reached in the Upper Coblentzian, and horizon near the top 

 of the American LTpper Helderberg (corniferous) group. The 

 species has for a long time been known to have a crenulated 

 hinge line. This feature was illustrated by Sclmur,* and by 

 Kayser,f and I believe also by the Sandbergers in their classic 

 work on the fossils of the Rhenish series in Nassau (this vol- 

 ume is not just now at hand ; hence it is impossible to give 

 the exact reference to the plate and figure). 



3. Chonetes (Eodevonaria) melonicus. — The presence of 

 crenulations on the hinge line of this species was noted, and 

 emphasized by Billings. Chonetes melonicus was described^ 

 from Little Gaspe, Quebec, Canada, in beds correlated with 

 the Oriskany, but which may prove to be a trifle higher than 

 the New York Oriskany. The species is certainly Lower 

 Devonian. 



L Chonetes {Eodevonaria) acutiradiata. — This species was 

 for a long time believed to have a smooth, non-crenulated 

 hinge. Indeed, Billings differentiated his C. melonicus from 

 this species by the crenulated hinge line of his Canadian form 

 while in C. acutiradiata the hinge was presumed to be non- 

 crennlated. In the Cornell University collections there occur 

 several typical specimens of C. acutiradiata from the Cornif- 

 erous limestone near Williamsville, Erie County, N. Y., all of 

 which show plainly the crenulated hinge line. 



5. Chonetes {Eodevonaria) extensus Kayser. — This large 

 very broad Chonetes was described by Kayser§ from Katze- 

 nelnbogen in the Rhenish middle Lower Devonian (Lower 

 Coblentzian). The denticulated hinge line is quite plainly 

 apparent in both his figures. 



6. Chonetes {Eodevonaria) arcei Ulrich. — This species 

 occurs at very nearly exactly the same geological horizon of the 



*Schnur. In Ubergangsgebirge der Eiffel vorkommende Brachiopoden. 

 Palaeontographica. vol. iii, PI. XLIII, figs, la, le, 1853. 



f Kayser. Die Fauna des Hauptquartzits und der Zorger Schiefer des 

 Unterharzes. Abhandl. d. Kgl. Preussischen geologischen Landesanstalt, 

 Neue Folge, Heft I, PI. XII, fig. 3, 1889. 



% Billings, Paleozoic Fossils, vol. ii, Part I, p. 15, fig. 6, 1874. 



§ Kayser, Fauna des Hauptquartzits, 1. c, pp. 64, PI. XXII. figs. 5, 6. 



