BY R. ETHKRIDGE, JUNR., AND JOHN MITCHELL. 495 



Staurocephalus murchisoni Bariaiule, 

 (Plate xxvii , figs. 6- 11 and 13). 



S. murchisoni Barrande, /oc. dt., p. 53; Syst. Sil. Bohenie, 1 te. 

 pt.,i., 1852, P1.43,figs.28-32; Salter, Mon. Brit. Trilobites, Pt. i., 

 1864, p. 84, PI. vii., figs. 13-20, Stcmrocephiihis near S. murchi- 

 soni Ratte, Proc. Linn. Soc. X. S. Wales, ii. (2nd ser.), Pt. i., 

 1887, p.lOO, PI. ii., tigs. 5-9. 



06."?. —After careful examination of numerous specimens of 

 Staurocephalus from Bowning, we are unable to separate our 

 species from S. murchisoni. In some of the figures of this species 

 given hy Salter (loc. cit. above), the free cheeks are shown to join 

 the glabella anteriorly just behind the glabella frontal lobe. In 

 one figure, however, it is shown to junction much in advance of 

 this, and well on the globular front lobe. This latter seems to be 

 the manner in w4iich the free cheeks are attached in the Bowning 

 species. The pleural appendages, both of the thorax and pygi- 

 dium, in ours are similar to those of the same parts of the Euro- 

 pean .S'. murchiaoni, but those borne by the pygidial pleurie, if 

 truly represented by Salter, are somewhat longer than they are 

 in the Bowning specimens. The dimensions of the European 

 and New South Wales forms agree 



Loc. and Hor. — Bowning Creek, Parish Bowning, County 

 Harden : Lower Trilobite Bed, Bowning Series (Yass-Hume 

 Beds). Upper Silurian. 



Staurocephalus(?) clarkii De Koninck. 



S. clarkii De Koninck, Foss. Pal. Nouv. Galles du Sud, Pt. i., 

 1876, p.47, PI. i., figs.13, 13a. 



Obs. — We have never seen a New South Wales trilobite ap- 

 proaching De Koninck's figures, portion of a cephalon and a pygi- 

 dium. If a Staurocephalus^ it is certainly a very abnormal species. 

 With the Upper Silurian S. murchisoni, these portions have no 

 relation, but *S'. (?) unicus Wy. Thomson,* has somewhat similar 

 glabella-furrows, although only two, instead of three, as in the 

 present instance, but there the diff"erence ends. The pygidium 

 associated with this fragmentary glabella is quite unlike that of 



* Salter, Mon. Brit. Tcilubites, Pt. i., 1864. PI. v., tius.22a and r. 



