Palaeozoic B haloed Entomostraca. 251 



largest and overlapping the right ; a short spine is occasion- 

 allj present on the postero- ventral region, and sometimes a 

 dark round spot in the centre of the valve ; lateral contour 

 elongate-ovate or subcuneiforra. Shell thick ; surface smooth. 

 Length -^^ inch. 



Usually referred to this species is a form (fig. 7) similar in 

 size and general character, but with the dorsal border arched 

 and the posterior extremity obtusely pointed. Tliis we con- 

 sider a variety. 



B. cuneola is common in the marine shales of the Carbo- 

 niferous-Limestone series in Scotland, and in similar deposits 

 of the Yoredale rocks in England. Discovered by Mr. John 

 Young, F.G.S. 



We are not quite sure about fig. 7 ; but we have always 

 regarded it as belonging to B. cimeola, and have found it at 

 several places. 



Localities. Holker Park, Scales Green, Humphrey Head, in 

 Lancashire; Arnside, Sandside, Heversham, in Westmoreland; 

 Dun Quarry and Woodend Quarry, near Lowick, Ancroft, 

 Scremerston, Elsdon Burn, Penchford, in Northumberland ; 

 Brockley, Mousewater, and Haywood, near Wilsontown, 

 Brankumhall Quarry, Boghead, Robroystone, Meikle Earnock 

 Burn, Kennox Water, in Lanarkshire ; Darcy Quarry, Brun- 

 ston Colliery, in Midlothian ; Whitebaulks, Kinneil Mill, in 

 Linlithgowshire ; Seafield Tower, Gleniston Quarry, Wilkie- 

 son Quarry, Ravenscraig, in Fife ; and in many other places. 



B. cuneola also occurs in the Calciferous Sandstone at Linn- 

 house W^ater, opposite Oakbank Oil-works, Linlithgow; 

 River Esk above Gilnockie Tower, Dumfriesshire ; Back Burn, 

 Plashetts, Northumberland. 



3. Bythocypris (?) cornigera^ J. & K. 

 (PI. VLfigs, 8 a, 8 Z), 8 c, 9.) 



Cythere comiqera, J. & K., MS. 18G7, Trans. Geol. Soc. Glasgow, 

 vol. ii. p. 223. 



Suboblong, very convex, and quadrately horned behind ; 

 left valve largest and overlapping ; surface smooth ; lateral 

 contour subcuneiform. Length -g^ to yV inch. Old specimens 

 have the valves very tumid and the extremities truncate. 

 This species is evidently a near relation to B. cuneola, with 

 which it is often associated. Discovered by Mr. John Young, 

 F.G.S. 



Localities. Scales Green, Humphrey Head, in Lancashire ; 

 Ancroft, Penchford, Dun Quarry, near Lowick, in Northum- 

 berland; Brockley, Ponfeigh Burn, Mousewater, Calderside 

 Quarry, Kennox Water, in Lanarkshire ; Whitebaulks, Lin- 



17* 



