THE CAKBONIFEROUS POEMATIONS OF THE BRITISH ISLES. 503 



The species peculiar to these beds are: — Cypridina Youngiana^ 

 C. Grossarticuia^ O. Thomsoniana, Ci/therella obliqua, O. cequalis, Beij- 

 richiafodicata, B. biccesa, Kirhhya rigida, and Youngia rectidorsalis. 



Then comes the series of sandstones, grits, shales, and fireclays, 

 with a thin coal or two, representing the Millstone Grit. From 

 these beds we have no Ostracoda. 



Above them follow the Coal-measures proper, consisting of a 

 Lower series («), containing all the workable coals ; and an Upper 

 series (b) of red sandstones, shales, marls, and fireclays, with 

 Carboniferous fossils. In the Lower series Beyrichia arcuata, 

 Carbonia fabulina, 0. Rankiiiicma, and G. pungeyis are the common 

 Ostracoda. Cyioridina r^adiata and Carbonia ? bairdioides also occur 

 rarely. In the Upper series (b) C. fabulina, C. Mankiniana, and 

 C. pungens are found abundantly at an horizon about 400 feet from 

 the highest beds. These are the last occurring Carboniferous 

 Ostracods in Scotland that we have seen. The next appearance of 

 representatives of their tribe is in the Lower Permian Limestone of 

 Durham, where a group of seven species is found, six of which are 

 Lower-Carboniferous forms ; but these Carbonioi are not among them. 



2. ElfGLAND. 



§ 1. In the north of England the lowest horizon from which we 

 have Ostracoda is somewhere near the base of the Scar Lime- 

 stone, as it occurs in JN'orth Lancashire and Westmoreland, and the 

 Lower Carboniferous beds in Cumberland and jSTorthumberland, 

 which are probably nearly equivalent in position, though very 

 different in character. Prom this or these horizons come the 

 following more common species : — 



Cypridina brevimentum^ Cypridinella Cummingii, G. superciliosa, 

 Cypridellina Burrovii, Cyprella chrysalidea, G. annulata, Polycope 

 Burrovii, Entomoconchus Scouleri, Entomis Burrovii, E. Koninckiana, 

 Gytherella valida, G. scrobiculata, 0. extuberata, Leperditia Oheni^ 

 L. suborbicidata, L. acuta, L. scotobiirdigalensis, L. subrecta, Beyrichia 

 craterigera, B. crinita, B. radiata, BeyricJiiopsis sicbdentata, B.fim- 

 hriata, Kirkbya costata, K. spiralis, K. umbonata, Argilloecia cequaliSf 

 Macrocypris Jonesiana, Bairdia Hisingeri, B. curta, B. plebeia, 



B. submucronata, B. subelongata, Bernix Tatei, &c. 



Higher in the limestone are also found, somewhat plentifully, 

 Kirkbya permiana, Leperditia Armstrong iana, Bythocypris bilobata, 

 Xestoleberis ? subcorbuloides, Bairdia amputaia, &c. 



The species peculiar to this portion of the series south of the 

 Border are: — Cypridina brevimentum, Cypridinella Cummingii^ 



C. monitor, Cypridellina Burrovii, Entomoconchus Scouleri, Entomis 

 Burrovii (and other of the Cypridinidae), Cytherella valida, Leper- 

 ditia subrecta, L. Armstrongiana, L. obesa, Beyrichia longispina, B, 

 tuberculospinosa, B. Holliana, B. crinita, Beyrichiopsis subdentata, B. 



fimbriata, Kirkbya tricollina, K. spiralis, Argilloecia cequalis, Macro- 

 cypris Jonesiana, Aglaia cypridiformis, Bythocythere antiqua, Cythere'i 

 Kirkbyana, C? gyripunctata, Darwinula berniciana, and Xestoleberis ? 

 subcorhuloides. 



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