Fossil Cjpridinidse and some Allied Ostracoda. 341 



9. From the extensive calcareous formation known as the 

 Mountain-limestone, including the Lower Carboniferous series 

 in Scotland, numerous genera and species allied to Ci/pridina 

 were described and illustrated in 1874 and 1884 in the 

 Pala^ontographical Society's Monographs, by T. Rupert 

 Jones, J. W. Kirkby, and G. S. Brady. Thus :— 



Number of 



Geuera. Species. 



Cypridina 13 



Bradycinetus .... 1 



Philomedes (?).... 1 



Cypridinella 7 



Cypindellina 8 



Cypridella 6 



Cyprella 2 



Sulcuna 2 



Rhombina 2 



Polycope 3 



Of a 1 



Entomoconchus . ... 3 



Leading Characteristics in the 

 Fossil Forms. 



Notch and beak, slight in some, more pro- 

 nounced in others. 



Beak produced and truncate. 



Notch deep and broad. 



Ovate, produced at each end ; more or 

 less apiculate behind ; antero-ventral 

 region projecting and prow-like. 



Like Cypridinella, but bearing a tubercle or 

 hump above the median line. 



Like Cypridellina, but having a dorsal 

 sulcus behind the tubercle. 



Nearly like Cypridella, but annulate. 



Subovate, with a deep and oblique sulcus 

 modifying the dorsal region ; front 

 truncate ; notch obsolete. 



Oblique-oblong; notch obsolete on the 

 front slope. 



Round or oval, with faint indication of 

 the notch. 



Subglubose; front edge truncate and im- 

 pressed by a nearly central slight in- 

 turning of the margins of the valves. 

 Subglobose ; front edge truncate and modi- 

 fied by the margins being pressed in- 

 wards, and each forming a sinuous 

 curve, which leaves a long-oval opening 

 below a short beak, and a narrower and 

 shorter slit in the ventral region. 



10. From the Coal-measures only a few (Jypridinids have 

 been obtained. Cypridina radiata, Monogr. Carb. Entom., 

 Pal. Soc, 1874, p. 14, pi. v. figs. Qa-Q f; and Philomedes 

 elongata^ Monogr. Carb, Entom. 1884, p. 81, pi, vi. figs. 1 a- 

 1 c. The former from Scotland, and the latter from England, 

 have both a peculiar radiate structure of the test. 



11. In a memoir by Professor G. G. Gemmellaro, "On 

 the Crustacea of the Fusulina-Wm^Biont of the Valley of the 

 Hosio River, in the Province of Palermo, Sicily," Mem. Soc. 

 Italiana delle Scienze fiss. e nat, vol. viii, ser. 3, no. 1, 

 40 pages, with 5 plates (4to, Naples, 1890), he refers to this 

 limestone as being a " Permo-Carboniferous " formation; 



