ON SOME NEW TRILOBITES FROM BOWNING, N.S.W. 



By John Mitchell. 



Bronteus longispinifex, n, sp. 



(Plate XVI. figs. 1 and 2.) 



Head-shield semicircular as far as can be judged from the 

 specimens obtained, much granulated, the granulations of varying 

 sizes. 



Glabella greatly dilated in front, axial and neck furrows distinct, 

 the front lateral groove feeble, second one strongly marked, facial 

 suture from the eye lobe to the outer mai'gin about parallel with 

 a line drawn longitudinally through the centre of the shield. No 

 spine visible on the genal angle, but from the character of the 

 pleurpe it is probable that it may bear one. The greatest transverse 

 measurement of the glabella about equal to the length of the head. 

 The eye is slightly pedunculated. Length of head-shield one and 

 a-third times (3) that of the pygidium. 



The thoi-ax is the most remarkable feature of this species, the 

 axis being very wide, moderately distinct and slightly arched ; 

 axial furrows visible and intensified by an increase of thickness at 

 the base of each segment, and an opposing tubei'cle at the base of 

 of each pleura ; the segments have a decided curve forward ; width 

 at the fifth segment -1354 inch (J^ in.), and this is probably the 

 greatest width. From the sixth the width gradually diminishes, 

 and the last is only about half the width of the fiith and sixth 

 segments. The side lobes are very narrow, the pleurae being only 

 about one-quarter as long as the axis is wide at its fifth and sixth 

 segments. From each pleura projects a flat spine more than three 

 times its own length ; these carve backwai-ds more and more 

 until the last three are parallel or nearly so with the axis ; along 



