408 Dr. H. Woodward—Bronteus from Devonian, Eifel. 
In his Devonian Fauna of the South of England the late Rev. G. F. 
Whidborne (Pal. Soc. Mon., pp. 32-42, pl. ili, 1892) describes and 
figures six English species of Bronteus, and remarks upon the difficulty 
of determining them by reason of the fact ‘‘ that with the one exception 
of B. flabellifer, Goldfuss (in Mr. Vicary’s collection), none of the 
heads and tails have occurred in contact’’. Besides this, the specimens 
are generally very imperfect, and ‘‘ except in the case of the Bohemian 
species many of the foreign ones have been described from the pygidia 
alone”’ (op. cit., pp. 32, 33). 
Although the pygidia of many species of Trilobites can hardly be 
relied upon for purposes of determination, those of the genus Bronteus, 
as pointed out by Barrande, are often extremely well marked and 
characteristic. This happens to be the case with regard to Mr. T. M. 
Hall’s specimen of a detached pygidium from Gerolstein, and I am 
encouraged, therefore, to offer a figure and description of it here. 
Fic. 1. Bronteus Halli, sp. nov. (pygidium). Lower Middle Devonian : Gerolstein, 
Eifel. The original specimen is preserved in the Townshend Hall 
Collection in the Atheneum, Barnstaple. Enlarged twice nat. size. 
Description of Mr. Townshend Hall’s specimen. (Fig. 1.) In out- 
line the broadly expanded tail-shield or pygidium is nearly 
circular, though somewhat truncated for 20mm. along its anterior 
border, where it articulated with the thorax, its extreme breadth 
being 80mm. and its length 28mm., presenting with its coalesced 
radiating ribs the appearance of an elegant fan. The surface is but 
slightly convex, with the exception of the small triangular, much 
elevated, central area on its anterior flattened border, which is, in fact, 
the distal extremity of the median axis of the trilobite, being also the 
point of articulation between the pygidium and the last free and 
movable segment of the thorax. From this triangular raised axis, 
which is 8mm. in breadth and 5mm. in length, radiate fourteen 
rounded ribs, seven on either side of the median raised ridge, this 
latter being much wider and not bifurcated; it is, indeed, a pro- 
longation of the distal end of the triangular axis. The first rib, 
which forms the latero-anterior margin of the pygidium, is strongly 
curved downwards and is broader near its centre than the six which 
follow; the others are about of equal thickness; they are all more 
slender at first, but become gradually stouter as they approach the 
