Contributions to Palceontology. 



147 



the original crust. Lateral lobes with three ribs besides 

 the anterior one : ribs divided by a groove. 



The cheek, fig. 48, was found in the same association. 



Up to this time, no glabella of Concephalites has been found 

 in the specimens from Osceola mills, and the pygidium is referred 

 to that genus on account of its similarity to some in the preceding 

 group of species. The pygidium associated with C.perseus is slight- 

 ly binodose on the posterior annulation, but its form and the propor- 

 tions of its parts are very different. 



There are, besides those above described, a group of 

 species with a moderately convex (rarely more prominent) 

 glabella, which in some of them is angular along the 

 middle, with faint glabellar furrows. In several of the 

 species, the facial suture apparently cuts the anterior 

 border at a distance from the apex ; and with narrow 

 fixed cheeks, they have a prominent palpebral lobe limited 

 by a distinct groove, while the posterior limb of the fixed 

 cheek is comparatively narrow. These species might be 

 referred to Dikelocephalus, but for the conical glabella, 

 and obscure furrows which do not extend entirely across 

 it. Three of the species which appear to be thus related, 

 have been designated by Dr. Owen respectively as Dike- 

 locephalus, Lonchocephalus, and Crepicephalus. Should 

 a separate designation be required for these, I would sug- 

 gest the adoption of the generic name Lonchocephalus. 



The species bearing the characters above indicated 

 are the Conocephalites winona, C. iowensis, C. wisconsensis, C. 

 hamulus and C. diadematus. 



The last named species has a more prominent glabella 

 than the others, and is more strongly marked by the gla- 

 bellar furrows, while the palpebral furrow is less distinct. 

 The C. ioivensis presents some distinctive features which 

 may render necessary its ultimate separation from the 

 genus. 



