THE CAEBONIFEKOirS FORMATIONS OF THE BRITISH ISLES. 501 



Cyiherella extuherata, and O. attenuata disappear, — until the Carbo- 

 niferous Limestone series is approached, when in the thin limestones 

 and associated shales begin to be seen species that are commoner in 

 the beds above. 



These remarks relate solely to what has been observed in the 

 Lower Carboniferous of Pife. In equivalent deposits in Mid-Lothian 

 and Linlithgowshire Ostracoda occur in great abundance in some 

 places, notably at the classical locality of Burdiehouse ; but the 

 general sequence of the record is less complete, and no other species 

 have been observed. 



§ 2. In the south west of Scotland, Dumfriesshire and Ayrshire 

 excepted, the Calciferous Sandstones contain few fossils of any kind, 

 and the only Ostracods recorded from them are Leperdit'm Okeni 

 and L. suhrecta, from the Lower or Hed Sandstone group («) of the 

 series. These two species are thus probably on a lower horizon than 

 any noticed in Fife, and hence are the first occurring and oldest of 

 known Carboniferous Ostracods. 



From low down in the Calciferous Sandstones of Dumfriesshire 

 and Ayrshire, though evidently in the Cement-stone group (6), we 

 have the following species : — Lep. Oheni^Beyr. subarcuata?,Argilloecia 

 cequalis, Bairdia pleheia, B. Hisingeri, B. brevis, and B. suhmucronata. 



From a group of limestones higher in position, in Dumfriesshire, 

 a more numerous suite of species occurs, including : — Kh-Tchya 

 umhonata, K. costata, Cytherella vcdida, 0. Benniei, Macrocypris 

 Jonesiana, Bythocypris hilohata, Cythere ? cuneola, C. ? cornigera, 

 Bairdia grandis, B. Hisingeri, B. amputata, B. ampla, and some 

 others. 



Lastly, in Eoxburghshire, these beds become richly fossiliferous in 

 Ostracoda. Washings of various shales and numerous mounted 

 specimens kindly sent us by the Geological Survey of Scotland from 

 localities in that county have given us the following list of species : — 



Leperditia Okeni. 



suborbiculata. 



Beyrichia radiata. 



subarcuata? 



intermedia ? * 



■ craterigera. 



Beyriehiopsis fimbriata. 



fortis. 



Xii'kbya plicata. 



spiralis. 



costata. 



umbonata ? 



Carbonia fabuliiia. 



Cytherella extuberata. 



attenuata. 



, sp. 



Cythere ? intermedia. 

 Argillcecia sequalis. 

 Bythocypris bilobata. 



subhmata. 



Bairdia Hisingeri. 



plebeia. 



ampla? 



subelongata. 



subraueronata. 



Cythere, sp. 



The Carbonia, although apparently estuarine, curiously occurs 

 here with several of the more decidedly marine forms. 



Of the species we have mentioned as found in the Calciferous 

 Sandstone series, the following appear to be confined to it : — Bey- 

 riehiopsis foi^tis, KirJcbya spiralis, Cytherella extuberata, C. attenuata, 

 Bythocypris sublunata, Argilloecia cequalis, Aglaia cypridiformiSf 



* A Silurian species. 

 Q. J. G. S. No. 168. 2 m 



