CYTHERELLA. 75 



Carapace convex, broad-ovate, one edge rather straighter than the other; pinched 

 anteriorly, convex medially and along the ventral region ; gently compressed behind. 

 End-view (of cast) inversely cordate. Muscle-spot distinct. 



Length 1'4; height - 92 ; thickness "64 mm. Proportions 35 : 23 : 16. 



Casts of this form, which we still place under Cytherella with some doubt, are not 

 common in the Carboniferous (marine) Shales of Craigenglen, 1 Campsie, collected by Mr. 

 John Young, F.G.S. It has also been collected by the Geological Survey of Scotland at 

 Burniebrae Burn, near Shield's Farm, not far from Milton of Campsie ; at Woodhall, 

 Water of Leith, in a band of marine shale in the Cement-stone group ; at Side old 

 quarry, Midlothian ; at the Salton Limeworks, new quarry, East Lothian, and at Sunny- 

 bank Quarry, near Inverkeithing. It occurs also in the Carboniferous Limestone of 

 Vise, Belgium, and in that of Hof, in Bavaria. 



12. Cytherella simplex, Jones 8f Kir/cby, MS. Plate VII, figs. 3 a, b. 



Cytherella simplex, J. fy K. Trans. Geol. Soc. Glasgow, vol. ii, 1867, p. 218; 

 vol. iii, 1871, Suppl., p. 28. 

 — — Armstrong, Young, fy Robertson. Cat. W.-Scot. Fossils, ] 876, 



p. 44. 

 — H. Woodward. Cat. Brit. Foss. Crust., 1877, p. 110. 



Carapace-valves broad-elliptical, slightly irregular on one margin ; strongly convex in 

 the middle, making an acute-elliptical profile. Smooth ; muscle-spot distinct. 



Length 1*12 ; height *8 ; thickness *64 mm. Proportions 28 : 20 : 16. 



Collected by the late Mr. Grossart in the Lower Limestone Series of Scotland, 

 350 fathoms below the Ell Coal, Rae's Gill, near Carluke.* 



13. Cytherella obesa. Sp. nov. Plate VII, figs. 10 a — c. 



Carapace small, subtrigonal-ovate, swollen on one margin, much less convex on the 

 other. Surface smooth, almost uniformly convex, but fuller behind than in front. 

 Profile narrow-ovate ; end-view blunt-oval. 



Length *32; height '24; thickness *18 mm. Proportions 16 : 12 : 9. 



From West Broadstone, 3 in the Beith District, in West Scotland, where the Lower 

 Limestone Series is very rich with Fossils. 



14. Cytherella (?). Sp. Plate VII, fig. 11. 



This is the internal cast of a subelliptical, moderately convex valve, straight on one 

 1 'Cat. W.-Scot. Foss.,' 1876, p. 70. - Ibid., p. 75. 3 Ibid., p. 67. 



