458 CARBONIFEROUS TRILOBITES OP AUSTRALIA, 



tions twenty, strongly arched; axial furrows distinct; side-lobes 

 strongly convex, their greatest width equals the anterior spread 

 of the axis; segments fourteen, all terminating at the inner 

 boundary of the narrow border. 



Ohs. — This very fine trilobite was described by Mr. K. Ether- 

 idge,* and was determined by him to be identical with his P. 

 dubia,j remarking, however, that the form now dealt with 

 differed from the Queensland one in the possession of eighteen 

 to twenty annulations in the pygidial axis, while the former had 

 only eight to ten. This of itself appears to the writer a sufficient 

 difference to justify the separation of the two forms specifically, 

 for, in no instance, has he found any Phillipsia, or indeed any 

 meinber of the Proetidse, presenting such a wide variation in the 

 axial annulations of its pygidium as is exhibited by these two 

 forms. But there are other differences between the two forms 

 of even greater specific importance than this one. The eyes 

 and front limb of the glabella of P. elovigata are relatively very 

 much larger than those of P. stanvelleiisis [P. dubia Eth. til.). 

 In the former, the facial sutures are more sinuate, the free 

 cheeks more depressed, eyes more squat on the cheeks, lateral 

 furrows of the free cheeks wider than they are in the latter. The 

 neck-ring and thoracic axial rings in the former are non-tuber- 

 culate basally; in the latter, these are tuberculate; the glabella 

 of the former, too, is relatively longer and straighter- sided than 

 is the case in the latter. The former has a relatively narrower 

 pygidial border, and is of a much larger growth than the other. 



The two forms, in many of their features, belong to the same 

 typical group of Phillipsise, in which the glabellte diminish in 

 width anteriorly, and are sub-bellshaped, and the facial sutures 

 strongly sinuate in front of the eyes. The British P. Lruncatula 

 is a good representative of the group. 



Log. and Hor. — Binge Berry, Rouchel Brook, Hunter River, 

 County Durham: (IjAllyn River, half a mile north-east of Gres- 

 ford; County Durham (Cullen). 



* Mem. Geol. Survey N. S. Wales, Pal. No.5, Pt. ii., 1892, pp. 126-8. 

 t Geol. and Pal. Queensland and New^ Guinea, p. 215, PL 8, fig. o. 



