488 CARBONIFEKOUS TRILOBITES OF AUSTRALIA, 



situated near the axial furrowy and border; the ribs apparently 

 extend into spines beyond the border, mesial furrows of the ribs 

 deep. Border of moderate width, and apparently only mildly 

 thickened. 



This pygidium, though it presents in a general way a 

 strong resemblance to that of Br. strzeleckii, exhibits features 

 which help to separate the two forms. The chief differences 

 between their pygidia are — l. The axis of Br. dunstani consists 

 of twelve or thirteen rings, as against ten in the other. 2. Five 

 longitudinal rows of tubercles traverse the axis of the former, 

 while seven rows occur on the latter on the same part. 3. A 

 large tubercle is situated centrally on each axial ring of the 

 former, but only on every alternate axial ring in the latter. 

 4. There is a smaller number of tubercles on each pleural seg 

 ment of the former than on the similar segments of the latter. 

 The pygidial ornamentation of our species agrees closely with 

 Br. lodiensis Meek. 



Dedicated to Mr. B. Dunstan, Chief Government Geologist, 

 Brisbane, whose palyeontological discoveries have been numerous 

 and important. 



Loc. and Hor. — Trilobite Ridge, Mt. Morgan, Queensland, 

 associated with P. ivoodivardi. Lower or Middle Carboniferous. 

 Specimens Nos.F1031, F 1007, Geological Museum, Dept. of 

 Mines, Brisbane; and No.712, Queensland Museum, Brisbane. 



Brachymetopus, sp. indet. 



\\\ addition to the head and tail, which served for the descrip- 

 tion of Br. daiisfaui, there occur on specimen No. 712 of the 

 Queensland Museum, Brisbane, no less than three pygidial frag- 

 ments of Brachymetopi, besides the pygidium which served for 

 the foregoing description of Br. dunstani. In the case of two, 

 one is partially superimposed on the other, and the tliird is 

 almost touching these. On specimen F 1007 is a portion of a 

 right cheek, which presents features evidently unlike either Br. 

 strzeleckii or Br. dunstani. Two of the fragmentary pygidia 

 also appear to be new, and maybe specifically identical with the 

 individual to which the cheek-fragment belonged. The material. 



