22 DEVONIAN FAUNA. 



5. Genus — Beyeichiopsis, Jones and KirJchy, 1886. 

 1. Bbyrichiopsis Roperti, n. sp. Plate III, fig. 17. 



Description. — Valve rather long, suboblong, flattish. Dorsal margin straight, 

 equal to about two-thirds of the length. Ventral margin nearly straight, 

 horizontal. Ends semicircular. Valve with (1) a small anterior lobe close to 

 the dorsal edge and defined behind by an oblique sulcus ; (2) a small indistinct 

 ventrally situated convexity, and (3) a large diffuse posterior lobe bearing in the 

 dorsal corner a small tubercle ; and (4) several longitudinal ridges on difierent 

 parts of the surface. Border bearing a narrow fringe. 



Size. — Length "8 mm. 



Locality. — There is one specimen from Pilton in the Porter Collection. 



Remarks. — It appears to me that this small fossil answers all the requirements 

 of the genus Beyrichiopsis, though it was only after the drawing had been made 

 that further examination brought out its true characters, and therefore they are 

 not well seen in the figure. 



Affinities. — The smaller size and different position of the lobes distinguish it 

 from B. fimhriata, Jones and Kirkby,^ and B. fortis, J. and K.,^ and B. suhdentata,^ 

 J. and K. The large subcentral boss in these species seems to be barely 

 represented in ours. 



6. Genus — Klcedenia, Jones and Hall, 1886. 

 1. Klcedenia bursjiformis, n. sp. Plate III, figs. 18 — 23. 



A series of variously distorted valves from a ferruginous weathered face of 

 limestone assume very diverse appearances, but probably all belong to one species 

 to the true shape of which figs. 18 and 21 perhaps represent the nearest approaches. 



Description. — Valve subovate, flattish. Dorsal edge long, straight, nearly 

 as long as the valve. Postero-superior corner angular. Free edges gently 

 •convex and bordered with a narrow rim. Anterior portion of the valve narrow. 

 Valve with two deep broad furrows, extending from the back for a greater or less 

 distance downwards and separating three elevated lobes, of which the first and 



1 1S86, .Jones and Kirkby, ' Geol. Mag.,' dec. 3, vol. iii, p. 434, pi. xi, figs. 3—10. 



2 Ibid., p. 4.35, pi. xii, figs. 1—3. 



3 Ibid., p. 437, pi. xii, figs. 1,2. 



