35 



the other hand, the axial grooves of/. Wahlenbergii, Barr.,^ 

 are considerably longer than those of our form, and more 

 or less circumscribe the glabella, and with these facts before 

 me, I think it better to distinguish the latter by a separate 

 name. 



Loc. — Zeehan, in the Despatch Limestone. 



Genus Cromus, Barrande. 

 (Syst. Sil. Boheme, 1852, I., p. 821.) 



Cromus Murchisoni, De Koninck. 



PI., Figs. 7 & 8. 



C. Murchisoni, De Koninck, Foss. Pal. Nouv.-Galles dii Sud, 1876, 

 Pt. 1, p. 54, t. 1, f. 8. 



Ohs. The larger portion of a cephalic shield and four 

 pygidia, all with the test removed. 



De Koninck has complicated the discrimination of this 

 and allied species by erroneous references to his figures. 

 For instance, he describes the head and tail of Encrinurus 

 Barrandei, De Kon., but refers to the figure (his Fig. 8, 

 PI. 1) only. He likewise describes the cephalic shield of 

 Cromus Murchisoni, and refers to the figures of both 

 cephalic shield and pygidium (his Figs. 9-9Z>, PI. I), at 

 the same time stating that both the thorax and pygidium 

 were unknown to him. In other words. Prof. De Koninck 

 reversed the numbers of the figures on his first plate. Fig. 

 8 should be Cromus Murchisoni, and Figs. 9-9^ should be 

 referred to Encrinurus Barrandei. That such is the case 

 is evident by bearing in mind the generic differences of the 

 cephalic shield of the two forms in question. 



In the Tasmanian specimens the larger portion of the 

 glabella, the neck segment and portions of the fixed cheeks, 

 are preserved. The positions of the glabella furrows are 

 distinctly marked by the large five primary tubercles on 

 each side, the furrows in the cast being short and some- 

 what wide. Between each of these points the surface is 

 occupied by four or five secondary tubercles ranged in a 

 line, whilst on the anterior part of the glabella smaller 

 tubercles of a tertiary order become numerous. The neck 

 segment is strong and wide. Neither of the pygidiums 

 are wholly preserved. There are twenty-six cr)alesced 

 segments at least in the axis, which tapers to a very fine 

 apex. The central line is devoid of segmentation, and 



' Syst. Sil. Boheme, 1852, 1., p. 684, 



