132 



Contributions to Palceontology. 



CONOCEPHALITES MINOR (Shumard). 

 PLATE III. FIGS. 1-4. 



Conocephalites minor : Shumard, Trans. Acad. Sciences of St. Louis, Vol. ii, 



p. 105. 



" Very small. Glabella well defined by linear dorsal fur- 

 "rows, subcircular, mnch elevated above the cheeks, 

 " regularly convex, slightly longer than wide, marked 

 " on either side with two short deep lateral furrows, 

 " which are directed obliquely backwards, and reach not 

 " quite one-third the distance across : neck-furrow linear, 

 " distinctly but not deeply impressed, sinuate, arched 

 "forward in the middle ; neck-segment short triangular, 

 "gently convex, not elevated, posterior angle terminating 

 " in a delicate acicular spine which is prolonged back- 

 awards, its length unknown; front margin narrow, con- 

 "vex; cheeks rounded, having very];delicate ocular 

 " ridges, which pass from the eyes in a short curve to 

 "reach the glabella a short distance in advance of the 

 " anterior glabellar furrow. Length of head^O-lO of an 

 " inch ; length of glabella, 0-08." 



Among a large number of specimens in my collection, 

 which I have referred to this species, there are some varie- 

 ties of form. A single specimen of the head destitute of 

 cheeks, which was kindly sent to me by Dr. Shumard, 

 from near the mouth of Black river, has a more rotund 

 form, and the glabella is proportionally shorter than in 

 specimens from Trempaleau, before regarded as unde- 

 scribed, but which I have now identified with the species 

 of Dr. Shumard. The sandstone of the Black river 

 locality is of somewhat different character, finer and more 

 compact ; and the difference in form may be due only to 

 physical conditions. 



