1G0 PALAEONTOLOGY OF ILLINOIS. 



and acutely pointed ; dorsal saddle as long as the dorsal lobe, 

 but wider and rounded at the extremity; superior lateral lobe 

 lanceolate, a little longer than the dorsal lobe, acutely pointed 

 at the end and somewhat contracted above; lateral saddle lin- 

 guiform, longer and narrower than the dorsal saddle ; inferior 

 lateral lobe similar to the superior, excepting that it is some- 

 what smaller; ventral saddle shorter and broader than the 

 lateral saddle, slightly oblique, and rounded at the end. 



As remarked by Prof. Hall, this species ,bears some remote relations to 

 Goniatites chemungensis of Vanuxem (Report 3d Geol. Dist. N. Y., p. 182), 

 but differs very materially in tbe number of its lobes, there being five or six 

 visible in each septum on each side of Vanuxem's species, and only two in ours. 

 It is much more nearly like G. mixohbus, Phillips, as figured in his Palaeozoic 

 Fossils, pi. LI, fig. 235 J, and Geol. Yorks., part II, pi. XX, fig. 43-47; but 

 presents well defined differences in its septa, particularly in the dorsal lobe. 

 Phillips's species is said to occur both in the Carboniferous and Devonian rocks 

 of England. 



As our description of the species under consideration was printed and dis- 

 tributed more than a month in advance of the publication of Prof. Hall's figures 

 and description, our name will have to take precedence, in accordance with the 

 established usages of naturalists. 



Should it ever be demonstrated that Montfort's type of Aganides was a true 

 Goniatite, the name of the species here described will of course become Agan- 

 ides Lyoni, since Montfort's name has priority of date. 



Locality and position: Rockford, Indiana, from the Goniatite bed of the 

 Kinderhook group. Subcarboniferous. 



