Messrs. Joues and Kirkby on Carboniferous Entomostraca. 35 



distinctions for nominal varieties. Thus L. Scotohurdigalensis 

 may be allowed to stand as a sufficiently distinct variety of L. 

 Okeni, though possibly it really differs only in having been 

 dwarfed by unfavourable circumstances of growth. 



In the Lower Carboniferous shales and limestone of Burdie- 

 house* we see Leper ditia Scotohurdigalensis in company with 

 Spirorbis (Microconchus) carbonarius (not very abundant there), 

 abundant Fish-remains, Lepidodendron, Lepidostrobus, Spheno- 

 pteris, &c. 



This smallest of the many varieties of Leperditia Okeni, oc- 

 curring in the Lower Carboniferous limestones and shales of 

 Great Britain and Ireland, has been found at Burdiehouse (by 

 Hibbert, Horner, Binney, Sorby, Crosskey, the Geological Sur- 

 veyors, and others) ; Granton (Harkness) ; Pittenweem, in Fife- 

 shire (Hunter) ; Bathgate (Young); Arundale, near Bathgate 

 (Young); Hurlet, S.W. of Glasgow (Crosskey); Carluke (Ran- 

 kine); Lammertou and Cockburnspath, Berwickshire (G. Tate); 

 and at many places in Ireland by Sir R. Griffith and the Geo- 

 logical Surveyors. (See further on.) 



One of us long ago saw that this little Entomostracan could 

 not be a Cypi'is, nor a Cythere, and put it with Cytheropsis (a 

 provisional genus). Hence it appears under that name in the 

 * Monograph of the Fossil Estheria' (Palseontographical Society, 

 1862) and in some other works. It was definitely referred to 

 Leperditia by us in 1863 (Brit. Assoc. Report, 1863, Sections, 

 p. 80; and 'Geologist,' vol. vi. p. 460). 



1836. Bean. — In 1836 Mr.W. Bean, of Scarborough, described 

 in the ' Magazine of Natural History,' vol. ix. p. 377, a little 

 Entomostracan from the Coal-measures of Newcastle-upon-Tyne, 

 as Cypris arcuata ; and illustrated it by a woodcut (fig. 55). 

 This is really a Beyrichia, and has been so referred to, on the 

 authority of one of us, for several years past. 



Beyrichia arcuata is one of the most widely distributed Ento- 

 mostraca in the Coal-measures of England and in the " Upper 

 Coal-measures'' of Scotland. It has also been found in the 

 shales of the so-called " Millstone-grit " of Lancashire and in 

 the Lower Carboniferous shales of Scotland, but not in the 

 Mountain-limestone, or equivalent portions of the Carboniferous 

 Series, in England. We have it from the Ryhope Colliery, near 

 Sunderland, in shale, about 8 or 10 feet below the base of the 

 Permian strata ; from Claxheugh, near Sunderland, in ironstone ; 

 from Hylton, near Sunderland, in ironstone; from Prestwick, 

 Northumberlandjin carbonaceous shale (Atthey); fromLoughton, 



♦ For a full account of the Carboniferous Strata of Burdiehouse, see 

 the ' Memoirs of the Geol. Survey,' &c. : " Geology of the Neighbourhood 

 of Edinburgh," by HoweU and Geikie, 1861, p. 36, &c. 



3* 



