BY JOHN MITCHELL. 467 



cheeks appear to have been small, and strongly tumid. Axial 

 furrows deep. Other parts not known. 



As Mr. Etheridge pointed out, this head-shield bears a strong 

 resemblance to that of some Proeti. The enormous limb is its 

 most striking feature. The discovery of a complete specimen 

 will be of much scientific interest. It may be noticed here that 

 neither of the figures, PL vii., fig. 13, PL xliv., figs. 5, 6 {loc. cit.) 

 are correct representations of the fossils they are intended to 

 depict. For example, in the case of the first of these, the 

 glabella is much too blunt in front; and supplementary lobes, 

 which are present on the fossil, are not shown in the figure. 

 With reference to figs. 5 and 6 of PL xliv., in the case of fig. 5, 

 the glabella is represented as of a battle-axe shape, instead of 

 being rather quadrate, or only gently rounded in front, and the 

 glabellar basal lobes are exaggerated in size. In fig. 6, the axis 

 is shown terminating much too short of the border, and, in the 

 pleural lobes, too many segments are shown. Photographs of 

 the original specimens, from which the drawings of the figures 

 above referred to were made, will be found in the Plates of this 

 paper. 



At present, I hesitate to recognise the portion of a cephalon 

 determined by Mr, Etheridge to belong to this species, and re- 

 presented in PL vii., fig. 13, for the following reasons. The 

 glabella of this specimen is much more convex and narrower in 

 front than the type-specimen. Further, this glabella is just as 

 long as wide across the basal glabellar lobes. On the other 

 hand, the typical glabella of the species is much wider across 

 these same lobes than it is long. The glabella in question is not 

 correctly represented by the figure above referred to, as will be 

 seen from the photos of it now produced. 



Since Mr. Etheridge described this species, much additional 

 material has been secured, and this has been placed with me by 

 Mr. Dunstan, Chief Government Geologist, Brisbane, for classi- 

 fication. Included in the collection is a large number of pygidia, 

 all possessing similar specific features; and these were collected 

 from the same localities from which all the known cephalic frag- 

 ments of the species have been obtained. In pait, owing to the 



