CYCLOPYGE ARMATA. 51 



defined margin. Anterior border of pygidium shows a strong fulcrum about 

 halfway out, with a more or less obsolete furrow behind it. 



Remarks. — The foregoing description is a revised summary of that given by 

 Salter (op. cit. 1864). In the Girvan area only pygidia of this species have so far 

 been recognised, and these are from Shalloch Mill and typical in all respects; the 

 Balclatchie specimens which have been assigned to it belong to Bronteopsis 

 ardmillanensis, as do those from Ardmillan in the Museum of Practical Geology. 



Winian has recently (1900) described this species from the Borkholm Beds in 

 the Silurian area on the Baltic, and he mentions in his specimens a small ridge 

 proceeding from the extremity of the pygidial axis to the margin which is absent 

 from the British examples. Judging from his figures, it seems likely that the 

 pygidia possessing this feature (Winian, <>]i. cit., p. 171, pi. v, tigs. 17 and ID) 

 should be referred to a form akin to Bronteopsis ardmillanensis. 



< Collection. — Mrs. Gray. 



Horizon and Locality. — Whitehouse Group (M. Bala) : Shalloch .Mill. 



Genus CYCLOPYGE, Corda. 

 1. Cyclopyge armata (Barrande), 1872. Plate VII, figs. 11—14 ; plate VIII, fig. 1. 



1872. JEytina armata, Barrande, Syst. Silur. Bohcine, vol. i, suppl., p. 59, pi. iii, figs. 1 — 14; pi. xv, 



figs. 16—19. 

 1880. Cyclo_py<je armata, Nicholson and Etheridge, Mon. Silur. Fuss. Grirvan, fasc. iii, p. 280, pi. xix, 



figs. 5—8. 

 1884. jEglina armata, Novak, Zur Kennt. bolnn. Trilob. (Beitr. zur Palseont. Oesterr.), p. 35, pi. xii, 



fig. 12. 

 1899. Cyclopyye armata, Mem. Gteol. Surv., Silur. Kocks Brit., vol. i, Scotland, pp. 517, 672, 688. 



Specific Characters. — Glabella suboval, gently convex, produced anteriorly into 

 a short rounded tapering frontal spine, but posteriorly truncated. Surface of 

 glabella marked by two pairs of well-marked transverse furrows, short, horizontal 

 or slightly arched, and isolated from axial furrows ; anterior pair of furrows 

 rather behind middle of glabella; second pair halfway between anterior pair 

 and posterior margin of glabella. Surface of glabella ornamented with fine 

 undulating raised lines transverse at base but concentric to lateral margins and 

 extending on to basal portion of frontal spine. Eyes (not Avell preserved in 

 the Girvan specimens) large, completely embracing sides of glabella and uniting 

 in front below spine with convex surfaces. Palpebral lobe narrow, band-like, 

 separated by a deep furrow from the glabella. 



Thorax imperfectly known. Axis more than one quarter the width of thorax ; 

 pleurce short with strong groove along whole length. 



