390 



by the labours of Mr. C. D. Walcott. So far as the 

 pygidia are concerned, those with broad flattened borders, or 

 limbs, and the posterior spines when present short and thorn- 

 like are DikelocephaU, whilst, on the other hand, similar 

 pygidia with the spines extending backwards from a broad 

 base long, narrow, and sharp ; or the spines in question 

 attached to the sides of the pleural lobes, appertain to 

 Crepicephalus . 



Loc. — Dolodrook River, Mount Wellington District, 

 Gippsland, Victoria (Chapman). 



Hor. — "Agnostus zone," Upper Cambrian (Chapman). 



Crepicephalus tasmanicus, Eth. fil. 



I>ikelocephalus tasmanicus, Eth. fil.: Proc. Rov. Soc. Tas., 

 1882 (1883), p. loo, pi. i., fig. 4. 



(?) Conocephalites stephensi, Eth. fil.: Loc. cit., p. 153, pi. i., 

 figs. 1-3. 



Obs. — Misled formerly by the descriptions of the late 

 Prof. James Hall, of Albany, I referred this pygidium to 

 Dikelocephalus , but it appears to be that of a Crepicephalus, 

 although not a highly typical one, owing to the narrowness 

 of the posterior portion of the limb. 



I am now of opinion that this pygidium, and the part 

 cephalon I described at the same time as Conocephalites 

 stephensi, will prove to be portions of one and the same 

 species. Since my paper was written, now many years ago, 

 I have examined a quantity of the Caroline Creek deposit. 

 One result of this is an inability to find any pygidia likely 

 to associate themselves with the "Conocephalites" cephalon 

 other than the "Dikelocephalus" tail, or vice-versa. I can, 

 therefore, only conclude they are one and the same. 



The cephalon called C. stephensi was, I believe, one of 

 the first, if not the first, Cambrian Trilobite portion to be 

 described in detail from Australasia. 



Loc. — Caroline Creek, near Latrobe, Tasmania (T. 

 Stephens). 



Hor. — Potsdam Sandstone or Lingula Flags (Etheridge) ; 

 "Dikelocephalus Group" (R. M. Johnston); Upper Cam- 

 brian (L. K. Ward); Cambrian (Etheridge). 



Genus Notasaphus, Gregory, 1903 

 (Proc. Roy. Soc. Vict., xv. (n.s.), pt. ii., 1903, p. 155). 



Notasaphus fergusoni, Gregory. 



N. fergusoni. Gregory: Loc. cit., p. loo, pi. xxvi., figs. 11-13. 



Obs. — The cephalon of Notasaphus, so far as known to 

 us, is certainly distinct from that of Dinesus, but if the figures 

 are a correct representation of the fossil, it is very difficult 



