CONTRIBUTIONS TO PALAEONTOLOGY. 147 



GENUS CONOCEPHALITES ( Zenker). 



I HAVE referred to this genus several species heretofore placed 

 under DiKELocEpHALus and Lonchocephalus by Owen; restricting 

 the former designation to the typical species of that author, which 

 are certainly very distinct from some of the others described under 

 that genus. Those species with the more conical and highly arched 

 forms of glabella were in part designated by Dr. Owen as Loncho- 

 cephalus, of which one character is the long spine projecting from 

 the base of the glabella. 



The generic description of Lonchocephalus is as follows : 



" Generic character. In this small and singular genus the highly 

 " arched glabella is either undivided, or has only two very 

 " obscure furrows. A spine of greater or less length projects 

 " backwards from the base of the glabella, in the median line 

 '* of the body over the thoracic segments ( fig. 12, Tab. I A). 

 *' The pygidium found associated in tlie same beds is semilunar, 

 " with little or no border, and has four segments of the axal 

 *^ lobe." 



The Genus Crepicephalus was created for other forms, of which 

 Dr. Owen speaks as follows : 



^' The rather flat slipper-shaped glabella is tapering and slightly 

 " acuminated anteriorly, with a faint ridge in the median line: 

 ** two small and very superficial depressions, and a posterior 

 " faint furrow, very partially divide the glabella. The facial 

 *' sutures run nearly parallel to the margin of the glabella, and 

 ** join a thickened cordlike anterior narrow border, enclosing 

 ** a convex area, narrower in front than at the sides. Oblique 

 ** plications can sometimes be traced on the cheek-plate in 

 *' advance of the eye, converging towards the apex of the 

 " glabella." 



We observe here also characteristics of the Genus Conocepha- 

 lites in the conical glabella with obscure furrows, and the ocular 

 ridges in the oblique plications, etc. ; while the only species de- 

 signated by Dr. Owen (the C. wis con sen sis) has a wide frontal 

 limb, and offers no means of distinction in the head from one 

 species placed under the Genus Lonchocephalus (the L. hamulus). 



