160 SIXTEENTH REPOKT ON THE CABINET OF NAT. HISTORY. 

 CONOCEPHALITES? BINODOSUS ( n. s.). 



ptATE VII. Fia. 47. 



A small pygidium occurring in the sandstone at Osceola mills, 

 differs from any of those before noticed. The axis is short, strong, 

 and abruptly elevated, with three rounded annulations besides 

 the terminal one, which is marked by two distinct nodes : these 

 nodes may have been spines in the original crust. Lateral lobes 

 with three ribs besides the anterior one : ribs divided by a groove. 



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



Up to this time, no glabella of CoNOCErnALiTES 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 G. jjcrseun is slighlly binodose on the posterior 

 annulation, but its form and the proportions 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 huve 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 tho conical glabel^, 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 Dikelocephalus, Lonciiocephalus and Crepicepha- 

 Lus. Should a separate designation be required for these, I would 

 suggest the adoption of the generic name Lonchocephalus. 



The species bearing the characters above indicated"^ are the 

 Conocephalites winona, C. ioivensisy 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 glabellar furrows, 

 while the palpebral furrow is less distinct. The C.iowensis presents 

 some distinctive features which may render necessary its ultimate 

 separation from the genus. 



