Victorian Fossils, Port XVIII. 167 



Fain. Cheiruridab, Salter. 

 Genus Cheirurus, Beyrich. 



Cheirurus sternbergi, Boeck sp. (Plate XV., Figs. 12, 13; Plate XVI., 



Fig. 22). 



TrUobites sternbergi, Boeck, 1827, Not. til laeren, Trilob., Mag. 

 for Naturvid., vol. VIII., p. 37. Burmeister, 1843, Organ, d. Tri- 

 lob., p. 132, pi. III., figs. 7, 8. 



Cheirurus sternbergi, Beyrich, 1845, Ueber bohm, Tril., p. 15, 

 fig. 4. Hawle and Corda, 1847, Prod. Monogr. d. bohm. Trilo- 

 biten, p. 135. Barrande, 1852*, Syst. Sil. Boheme, vol. I., p. 795, 

 pi. XLL, figs. 29-39. 



Description. — A rather undersized, but fairly complete specimen 

 found near Lilydale shows the eephalon and seven thoracic seg- 

 ments; the remainder with the pygidium having split off the rock, a 

 brittle mudstone, during extraction. The whole of the eephalon 

 has a granulate surface. The thoracic body rings are Avell marked 

 and the distal ends of the pleura are free, and curved downwards 

 to a greater degree than are shown in Barrande's fig. 31 on PI. 

 XLI. (loc. supra cit.). This specimen probably measured when 

 complete about 16 mm. in length. The width of the eephalon is 

 10 mm. 



The eephalon of a larger example, coll. by Mr. J. S. Green, from 

 Seville, measures 30 mm. in width and 21 mm. in length. The 

 greatest width of the glabella, in front of the anterior furrow, is 

 16 mm. 



Observations. — Several cranidia of a Cheirurus have been found 

 at various times in the Victorian Yeringian beds in the neighbour- 

 hood of Lilydale and Seville. The shape of the anterior part of the 

 glabella in these specimens and the character of the anterior and 

 median furrows in cutting transversely across the central area, 

 together with the inclined posterior furrow, which makes an 

 X-shaped figure with the neck furrow, shows it to belong to the 

 above species. 



The only other species comparable with the Victorian appears to 

 be C. gibbus, Beyrich. 1 This species, however, has a narrower 

 body, a more inflated glabella, straighter anterior and median fur- 

 rows, and a less salient anterior angle to the middle of the neck 

 ring. 



1 Ueber bohm. Trilob., 1845, p. 16, fig. 5. Also BarVande, Syst. Sil. Boheme, vol. i., 1852, p. 

 792, pi. xl., figs. 35-39 ; pi. xli., figs. 17-27 ; pi. xlii., figs. 12-15. 



