48 Messrs. Jones and Kirkby on Carboniferous Entomostraca. 



and lower boundaries, being in some places wholly " Carboni- 

 ferous/' at others wholly made up of " Old Red," and elsewhere 

 combining portions of each ; and they restrict the term to the 

 upper portion of the Old Red Sandstone series, distinctly below 

 the beds with marine fossils. They consider that the " Carboni- 

 ferous Slate" (about 150 feet thick), below the "Carboniferous 

 Limestone" (3000 feet), in the north-eastern districts, is the 

 same as the "Lower Limestone Shales" of England, and that 

 the " Carboniferous Limestone " thins away on the south-west 

 and is wholly replaced by the "Lower Limestone Shales" 

 (about 5000 feet), which are there cleaved, and therefore known 

 as " Carboniferous Slate." The latter, in consequence, are in 

 the south-west the equivalents of the "Carboniferous Lime- 

 stone " and " Lower Limestone Shales " together in the north- 

 east. 



As this arrangement simplifies the order and succession of 

 the " Lower Carboniferous " strata, we use both nomenclatures 

 in the annexed table of the Entomostraca that we have observed 

 in Sir R. Griffith's specimens. 



We have also seen other Carboniferous Entomostraca from 

 Ireland, which have been kindly submitted to us by the Officers 

 of the Geological Survey of Ireland. 



I. From the " Carboniferous Limestone." 



1. Meath (Map, Sheet 33/4); Clonalvy, near Naul. Entomo- 

 conchus Scouleri. 



2. Meath (Sheet 27/1) ; Duleek. Light-grey limestone. 

 Cypridina primceva (gregarious) . 



3. Dublin (Sheet 7/1) ; Oldtown. Leperditia Okeni. 



4. Tipperary (20/2) ; Carrig-Church, about 2^ miles north- 

 west of Nenagh. Dark-coloured Polyzoan Limestone, with 

 Echinoderm fragments and Shells. Leperditia subrecta. 



5. Limerick (Sheet 11/2); Ballynolan, near Paliaskenry. 

 Entumoconchus Scouleri. 



6. Limerick (10/4); Glenbane, near Askeaton (No. 4253 a). 

 Leperditia Okevi. 



7. Limerick (29/1); Rathkeale. Grey limestone with Fenes- 

 tella. Leperditia subrecta. 



8. Cork (76/3) ; Ballyvodock, about 2 miles south-west of 

 Middleton. Grey fossiliferous limestone. Entomoconchv^ Scou- 

 leri (gregarious). 



II. "Lower Limestone Shale." 



1. Londonderry; Ballrascreen. Hard dark-grey shale, mica- 

 ceous, full of small Leperditia. (Portlock's Collection.) L. sub- 

 recta, L. Scotoburdigalensis, and still smaller obscure forms. 



