BRONTEUS. 91 



fifth, but running nearly straight backwards. Doublure of pygidium broad and 



concentrically striated. 

 Dimensions. — 



Length of pygidium . . . 50*0 nun. (approx.). 



Width of . . 55-0 „ 



Length of axis . . . 24*0 „ 



Width of „ . . . 22-0 „ 



Eemarhs. — As Nicholson and Etheridge observed (Inc. cit), this form resembles 

 B. hibemicus, Portlock, but the axis of the latter was unknown to Portlock, and is 

 at any rate considerably narrower than in this Craighead species. It may 

 appropriately be distinguished by the specific designation grayi. 

 Collection. — Mrs. Gray (f. M.). 

 Horizon and Locality. — Stinchar Limestone Group (Llandeilo) : Craighead. 



4. Bronteus, sp. ind. (a). Plate XII, fig. 15. 



An epistome, probably belonging to one of the foregoing species of Bronteus, 

 is in Mrs. Gray's collection from Craighead. 



Description. — Shape transversely subfusiform, narrowing laterally. Anterior 

 border gently arched forwards. Lateral angles truncated obliquely at angles of 

 about 60° to front edge. Posterior border nearly straight, but bulging out 

 suddenly in middle to form blunt projection. Surface ornamented by 8 — 9 strong 

 transverse imbricating stria" 1 , the anterior 3 — 4 parallel to front e(\ge, the posterior 

 3 — 4 following outline of posterior margin, and the median ones straight. 



Dimensions. — 



Width between lateral angles on front margin . 12*0 mm. 



Length from back to front across middle . . 4"0 ,, 



Collection. — Mrs. Gray. 



Horizon anil Locality. — Stinchar Limestone Group (Llandeilo) : Craighead. 



5. Bronteus, sp. ind. (I>). Plate XII, fig. 10. 



There is a small imperfect head-shield of a species of Bronteus from Craighead 

 in Mrs. Gray's collection which is worthy of a separate description, though its 

 specific relations cannot be determined. 



Description. — Glabella very gently convex, clavate, expanding in front to 

 twice (?) basal width, without furrows or pits, but ornamented with slightly un- 

 dulating stria? arched forwards and concentric to a median point near the base of 



