322 



being bent down so that only half their length is seen in a view of the 

 upper side as represented in the above figure. 



In general there are only five segments in the axis of the pygidium of 

 an Amphion, but in A. Julius figured (ante, p. 290), there are ten, and 

 in this species eighteen. It is possible that all behind the fifth may be 

 regarded as equivalent of the long triangular terminal segment of such 

 species as A. Barrandei, A. Canadensis, and others. The general form 

 of this pygidium is also very like that of Encrinurus, a genus which is 

 very closely allied to Amphion. Indeed, if the specimens had been found 

 associated with the head of an Encrinurus, I would have had no hesitation 

 in referring them to that genus ; but there was not a vestige of anything 

 that could be identified as belonging thereto collected. On the other 

 hand the glabella and pygidium above figured were found in about equal 

 numbers together, and in great abundance. Out of one small piece of 

 rock scarcely a yard \n length, there were taken twenty-seven specimens 

 of the glabella, and twenty-four of the pygidium. In this mass of rock 

 there was no other head to which the pygidium could be referred, nor any 

 other pygidium to which the head could possibly have belonged. Not- 

 withstanding, however, this remarkable association, it is with great doubt 

 that I classify the specimens under one name, even provisionally. Should 

 a separation be hereafter found necessary, I beg that the specific name 

 may be retained for the head. 



Dedicated to Mr. T. C. WESTON. 



Locality and Formation. Stanbridge, range 6, lot 20 ; Quebec group. 



Collectors. J. Richardson; T. C. Weston. 



AMPHION CONVEXUS. (N. sp.) 



Description. Head strongly convex, apparently forming one-fourth of 

 a sphere. Glabella convex, oblong, uniformly rounded in front ; sides 

 straight and parallel ; dorsal furrows deep ; neck furrow all across ; three 

 pairs of glabellar furrows ; the second pair half-way between the neck 

 furrow and the front margin , the first pair a little nearer the neck furrow 

 than they are to the second pair; the third or anterior pair cutting 

 the anterior margin half way between the middle and the sides, and 

 extending obliquely inwards at an angle of about 45. The furrows 

 all extend inwards one-third the whole width. The eyes appear to 

 be large. A line drawn across the glabella at the mid-length would 

 pass through their posterior angles, and they seem to slope inwards 

 from this point towards the middle of the third lobe of the glabella. 

 The distance of the posterior angle of the eye from the dorsal furrow 

 is equal to nearly half the width of the glabella. The cheeks are 

 somewhat coarsely pitted. 



