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,' 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 Earm, 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 Kirkby, MS. Plate VII, figs. 3 a, b. 



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



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



— — Armstrong, Young, Sc Robertson. Cat. W.-Scot. Fossils, 1876, 



p. 44. 



— — H. Woodivard. 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,^ 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. 2 Ibid., p. 75. ^ ibid., p. 67. 



