CONTRIBUTIONS TO PALAEONTOLOGY. 161 



CONOCEPHALITES WINONA ( n. s.). 



PLATE VII. FIGS. 26 - 28. 



Compare Conocephalites chippewacnsis (=? Lnrxhocephalus chippewaensis, Owen) ; 

 Shumard in Trans. Ac. Sciences of St. Louis, VoL ii, p. 104. 



Head small. Glabella cylindrico-conical, sides gently curving to- 

 wards the front which is regularly rounded, sharply truncate 

 behind by a straight narrow occipital furrow : glabellar furrows 

 obscure or obsolete. Occipital ring rounded, lower than the 

 glabella, narrow at the sides, and produced in the middle. Dor- 

 sal furrow abrupt, strongly defined at the sides and little less 

 strongly in front : cheeks abruptly rising from the dorsal furrow, 

 rounded above, and extended in the direction of the palpebral 

 lobe. Frontal limb a little depressed below the plane of the 

 cheeks adjacent to the glabella, and marked by a sharp trans- 

 verse groove which is little less distinct than the dorsal furrow ; 

 and anterior to this the margin is elevated as high or higher 

 than the part behind the groove. A slight central longitudinal 

 groove or depression extends across the posterior part of the 

 frontal limb, from the dorsal furrow to the frontal furrow. 



Associated with numerous specimens of the glabella and fixed 

 cheeks are many fragments of movable cheeks, and one or two 

 nearly entire. The cheek is small, rather flat, with a strong thick- 

 ened rounded border, which is prolonged into a spine as long as 

 the body of the cheek. Eye large, semilunar, and abruptly elevated 

 from the cheek. 



Caudal shield (of this species?) nearly semielliptical, a little 

 curved on the anterior margin : axis abruptly elevated, rounded, 

 marked by about five annulations including the terminal one. 

 Lateral lobes depressed convex, having three flattened simple ribs 

 besides the anterior one, all terminating in a narrow flattened 

 border. 



One of the most marked features of this small species is the abrupt 

 termination of the glabella behind ; the lower angles not being rounded, 

 while the occipital furrow is very trenchant. The glabella is less gibbous 

 than in C. minor, and does not slope to the occipital furrow : the occipital 

 ring is narrower, not triangular, and less produced posteriorly ; the cheek 

 is narrower, the border stronger, and the eye larger. In the caudal shield, 

 the axis is more prominent, the lateral lobes more convex, and the ribs less 

 elevated without perceptible grooves. 



This species is associated with G. iowensis, Obolella? and Lingula, 

 on the banks of the Mississippi opposite the mouth of the Black river, in 

 specimens received from Dr. Shumard. 



[Senate, No. 115.] 21 



