112 CARBONIFEROUS AMMONOIDS OF AMERICA. 



Family AGANIDID^. 



Grenus Aganides de Montfort. 



1884. Brancoceras, A. H.yatt (not Brancoceras Steinmann, 1881). 

 1898. Aganides, E. Haug, Etude.s sur les Goniatites, p. 39. 

 1901. Aganides, F. Freeh, Ueber devonische Ammoneen, p. 7-4. 



Aganides rotatorius de Koninck. 



PI. XVI, fig-. 19; PI. XIX, figs. 12-14. 



lSl:2-181:-±. Ammonites rotatorius, L. G. de Koninek, Descr. auim. foss., p. 565, 



PI. LI, fig. 1. 

 1852-1854. Goniatites rotator im, F. Roenier, Letha^a Geognostica, 3d cd.. Vol. I, 



Ft. II, p. 51, PI. I, tig. 16. 

 1860. Goniatites rotatorius ? , James Hall, Thirteenth Rept. N. Y. State Cah. Nat. 



Hist., p. 101, figs. 15 and 16. 

 1860. Goniatites imon, James Hall, Thirteenth Rept. N. Y. State Cab. Nat. Hist.. 



p. 125, figs. 1-3. 

 1876. Goniatites rotatorius, James Hall, lUustr. Devonian Foss. Cephal. . PI. LXXIII. 



tigs. 12-14. 

 1870. Goniatites rotatorius, F. Roemer, Lethtea Geognostica, Pt. 1. Letluea Paleo- 



zoica, PI. XLVI, tigs. 12a, b. 



1879. Goniatites i.rion. James Hall, Pal. N. Y., Vol. V., Pt. II. p. 474, Pi. LXXIII, 



figs. 12-14; Pi. LXXIV, fig. 12. 



1880. Goniatites rotatorius. L. G. de Koninek. Fauiio ealc. carbon, de la Relgique, 



Vol. I, p. 246, PI. XLVII, tig. 12. 

 1884. Brancoceras ixion, A. H_yatt, Proc. Boston Soc. Nat. Hist., Vol. XXII, p. 



326. 

 1886. Brancoceras i.eion, James Hall, Fifth Ann. Rept. N. Y. State Geologist, 



PI. XIII. fig. 3. 

 1888. Brancoceras i.don, C. E. Beecher, Pal. N. Y., Vol. V, Pt. II, Supplement, p. 



40, PI. CXXVIII, tig. 3. 



1897. Brancoceras ixion, Foord and Crick, Catal. Foss. Ceph. Brit. Mus., Pt. Ill, 



p. 141, fig. 62. 



1898. ? Brancoceras rotatorium, ^l. Tzwetaev, Mem. Com. Geol., Vol. VIII, No. 4, 



p. 28, PI. V, 19. 

 Is98. Aganides rotatorius, E. Haug, Etudes sur les Goniatites, p. 39. fig. 9e. 

 1901. Aganides ixion, F. Freeh, Ueber devonische Ammoneen, p. 74, fig. 32c. 



This species, which is very common at Rockford, Ind., but unknown 

 anywhere else in America, is quite easily recognizable. The following 

 description is based on a number of specimens from Rockford. 



Discoidal, compressed laterally, with sides sloping gently to the 



