134 



Contributions to Palceontology. 



This small species is very common in the sandstone at Trempaleau, 

 associated with C. iowensis, Lingula ampla, Obolella f and Pugiun- 

 culus or Theca. Dr. Shumard cites the Conocephalites (Lonchoce- 

 phalus) chippewaensis as occurring in the same association, near the 

 mouth of Black river on the Mississippi. The original C. (£.) 

 chippewaensis of Owen is cited by the author as from the fourth or 

 Marine-mills trilobite bed, while the C. minor is in the lower trilo- 

 bite bed. 



The following species of Conocephalites is from the Potsdam 

 sandstone of New York : 



CONOCEPHALITES MINUTUS. 



PLATE III. FIGS. 5, 6 & 7. 

 Conocephalites minutus: Bradley^ Am. Jour, of Science, Vol. xxx, p. 241. 1860. 



Head semicircular, somewhat straight in the middle of the 

 front, with the posterior angles of the cheeks produced 

 into spines which are more than half as long as the cheek- 

 shields. 



Glabella very gibbous, ovate conical, a little longer than 

 the width at the base, slightly narrowed behind; marked 

 by three pairs of glabellar furrows, the anterior ones 

 being usually obscure : occipital ring prominent in the 

 middle, and produced into a spine, which, measuring 

 from the occipital furrow, is about three-fourths as long 

 as the glabella. Occipital furrow narrow and well denned. 

 Dorsal furrow narrow, somewhat sharply denned, and 

 continued of the same strength in front of the glabella. 



Fixed cheeks comparatively wide, with the posterior 

 limb short : ocular ridges distinct, reaching the dorsal 

 furrow just behind the anterior glabellar furrow. 

 Frontal limb extending, with a, thickened and ele- 

 vated anterior border which is a little wider in the 

 middle. 



Movable cheeks narrow, with ocular sinus comparatively 

 large : the border is thickened and produced in a slen- 



