56 CARBONIFEROUS ENTOMOSTRACA. 



the Muscle-spot in the normal position, that is, in the antero-inferior region and towards 

 the sloping margin. 



Plate V, figs. 1 a — d. — Shells ; magnified eight diameters, and ornament more 

 highly magnified ; from Braidwood, Carluke. 



3. PoLYCOPE YouNGiANA, /. and K. Plate V, figs. 2 a—f. 



Cythere? Youngiana, /. Sf E., 1867. Trans. Geol. Soc. Glasgow, vol. ii, p. 223. 

 CypRiDiNOPSis — — 1871. lb., vol. iii, Suppl., p. 26. 



Carapace ovate, somewhat narrower in front, and slightly pinched in or incurved at the 

 anterior third of the ventral edge, without any definite notch being produced. End-view 

 acute-oval. Edge-view long-acute-oval. Surface ornamented with long, concentric, inter- 

 lacing or anastomosing and raesh-like strise, very much like the ornament of Cypris 

 striolata, Brady ('Annals Nat. Hist.,' ser. 3, vol. xiii, pi. 3, fig. 15). The ventral edge of 

 at least the right valve has a marginal rim. 



Length -^ ; height ^ ; thickness -j^ inch. Proportions 9:6^-. 5. 



The specimens are pyritous, and were collected by Mr. John Young, Assistant- Curator 

 of the Hunterian Museum in the University of Glasgow, in a marine shale of the Carboni- 

 ferous series at South Hill Pit, Campsie. " Rather rare. A very local species. Lower 

 Limestone, South Hill, Campsie ; in dark-blue shale above the Hosie Limestone, with 

 Goniatites, Bellerophon, Nucida, and Spirifera TJrei ; Carluke ; in an ironstone nodule, 

 in shale, Eirst Kingshaw Limestone" (Suppl. supra cit., p. 26). 



The species is named after Mr. John Young, of Glasgow, one of the energetic palaeon- 

 tologists of Western Scotland who are successfully working out the natural history, 

 geology, and fossils of Lanarkshire and the neighbouring districts. 



