148 J. W. Dan's — Carboniferous Fish-remains. 



region. The convexity is greatest along the ventral region, causing 

 this part to swell out a little beyond the ventral margin. Edge view- 

 oval with sharp ends; end view short-ovate, acute above, broad 

 below. Eare. 



This distantly resembles the smooth variety of Cytheridea torosa 

 (Jones), Monogr. Tert. Entom. 1856, p. 21, pi. 2, fig. le ; var. teres, 

 Brady (Trans. Linn. Soc. 1868, vol. xxvi. p. 425, pi. 28, figs. 7-12; 

 Aun. Mag. Nat. Hist. 1870, ser. 4, vol. vi. pp. 21, 22, note ; Monogr. 

 Post-Tert. Entom., Pal. Soc. 1874, p. 178, pi. 7, figs. 1 & 2). The 

 anterior hinge, however, is more definite, though not prominent, the 

 shape is rather more truly oblong, and the sub-medial impression is 

 not so strong. As I have not seen an interior of a valve, I cannot 

 say if this American species belongs to Cytheridea or to Cytherideis. 



Table of Proportion's. 



Length. Height. Thickness. 



Metacypris Forbesii, Fig. 1 15 9 11 



M. Bradyi, Fig. 2 18 10 10 



M. Whrtei, Fig. 3 18 9 8 



Darwinula leguminella, Fig. '4 14 6 5 



Cypris Purbeckensis, Fig. 5 -. 13 6 5 



Cytherideis Marshii, Fig. 6 13 7 5 



Cytheridea? atlantosaurica, Fig. 7 12 6 6 



If these proportional numbers be divided by 15, the result will 

 be linear dimensions in a millimetre and parts of a millimetre; the 

 figures being magnified 15 diameters. 



As the anterior extremity is placed upwards in the figures, the 

 height of the valves appears as width on the plate. 



The species Eigs. 1, 2, 3, 4 are abundant; those shown by Eigs. 5, 

 6, and 7 are rare. 



EXPLANATION OF PLATE IV. 

 (The figures are magnified 15 diam.) 



Throughout a is the side view ; b, edge view ; c, end view of the hivalved carapace. 



Fig. 1. Metacypris Forbesii, Jones; a, right valve outwards. 



,, 2. M. Bradyi, Jones; a, right valve outwards. 



,, 3. M. Whitei, Jones; a, left valve, outwards. 



,, 4. Darwinula leguminella (E. Forbes) ; a, right valve outwards. 



,, 5. Cypris Purbeckensis, E. Forbes ; a, left valve outwards. 



,, 6. Cytherideis Marshii, Jones ; a, left valve outwards. 



,, 7. Cytheridea ? atlantosaurica, Jones ; a, left valve outwards. 



II. — Notes on a Collection of Eossil Fish-Eemains from the 



Mountain Limestone of Derbyshire. 



By James "W. Davis, F.G.S. 



I AM indebted to Thos. Parker, Esq., of Oldham, for the oppor- 

 tunity he has afforded me of examining his large collection of 

 fish-remains from the Carboniferous Limestone of Derbyshire. The 

 specimens have been obtained from quarries near Chapel-en-le-Frith, 

 in the N.W. of the county. They are for the most part in a beautiful 

 state of preservation, though some of the more fragile specimens are 

 only obtained with the most careful manipulation on account of their 

 liability to fracture. The fossils are creamy- white in a light-coloured 

 crystalline limestone matrix. 



