'322 E. Billings on some oj the 



Locality and formation. — In the upper limestone at Phillips- 

 burgh. 



Amphion Salteri. N. sp. 



Fig. 6. 

 Fig. 6.— Head and tail of Amphion Salteri. 



Description. — Head about three lines in length and five lines 

 in width at the base. Glabella convex, oblong, one-third the 

 width of head, with straight sides, front obtusely rounded and 

 slightly narrower than the bease ; neck furrow extending all across ; 

 three pairs of glabella furrows inclining slightly backwards ; their 

 inner extremities separated by about one-third the width of the 

 glabella. The margin in front of the glabella is scarcely half a 

 line in width. The fixed cheeks are separated from the glabella 

 by a deep groove on each side. The eye appears to be opposite 

 the second lobe of the glabella from the neck furrow and distant 

 about three fourths of a line fram the furrow which separates the 

 cheek from the glabella. The fixed cheeks appear to be covered 

 with small tubercles. 



The pygidium has the front margin rounded and the posterior 

 somewhat straight. The axis is conical and strongly convex with 

 five or six segments, well defined. The pleurae of the pygidium 

 are five on each side and in their posterior half or two-thirds 

 nearly parallel with the axis and then curve inwards to join the 

 axial segments. Length of pygidium about three lines ; greatest 

 width at about one-third the length three lines at which width 

 (nearly) it continues to the posterior margin. 



Cheeks and Thorax unknown. 



Affinities. — The tail of this species very closely resembles that of 

 A. Canadensis but the glabella at once shews it to be distinct as 

 all three pairs of glabellar furrows are in the sides while in A, 

 Canadensis the front pair are placed in the front margin. There 

 is no other described species to which this is closely allied. 



The head and tail have not been seen in connection, but they 

 are often found in the same slabs of stone, and as there is not 

 associated with them any other pygidium to which the head could 



