MM. Jones and Kirhby — On Carboniferous Ostracoda. 535 



tangential section of an Ayrshire example of Solenopora compacta 

 (PI. XIII. Fig. 3) with a corresponding section of a Russian specimen 

 (PI. XIII. Fig. 6), the two being drawn to the same scale. As above 

 said, the Canadian specimens and the Russian are in this respect 

 alike. It may, therefore, be as well to consider the Aj'rshire 

 specimens as constituting a variety of the species under the name of 

 Solenopora compacta, var. PeacMi. 



EXPLANATION OF PLATE XIII. 



Fig. L An example of Solenopora compacta, Bill, sp., from the Ordovician 



Limestone of Saak, Esthonia. Natural size. 

 ,, 2. Vertical section of a specimen of Solenopora compacta, var. Peachii, 



Nich. and Eth. Jun., from the Ordovician Limestone of Craighead, 



Girvan. Enlarged ahout fifty times. 

 „ 3. Tangential section of the preceding, similarly enlarged. Both these 



sections show the fissiparous development of the tubes. 

 „ 4. Part of a long section of a specimen of Solenopora compacta, Bill., 



from the Trenton Limestone of Prince Edward's County, Ontario. 



(Coll. Dr. George J. Hinde.) Enlarged about one hundred and 



fifty times, and showing the curious concentric banding of the fossil. 

 ,, o. Tangential section of the preceding specimen, similarly enlarged. 



,, 6. Tangential section of a specimen from Saak, Esthonia. Enlarged 



fifty times. 

 ,, 7, 8. Tangential sections of another specimen from Saak, showing difEerent 



conditions of preservation of the walls. Both sections show 



numerous septiform processes due to the fission of the tubes. 



Enlarged one hundred and fifty times. 

 ,, 9. Part of a vertical section of Solenopora compacta, var. Peachii, 



enlarged fifty times, showing a true concentric line of growth. 



Craighead, Girvan. 

 ,, 10, 11. Vertical and tangential sections of a recent Nullipore, enlarged one 



hundred and fifty times. 



mi 



II. — Notes on the Carboniferous Ostracoda of the North-West 



OF England. 



By Professor T. Eupert Jones, F.E.S., and Jambs "W. Kirkbt, Esq. 



Introduction. 



^HE following notes and lists of species are based upon material 

 JL collected by one of us during several visits to the neighbourhood 

 of Grange-over-Sands, Lancashire. They are here recorded because 

 they add a little to what is known of the distribution of Bivalved 

 Entomostraca in the North-West of the English area during the early 

 half of the Carboniferous Period. 



The localities from which we obtained our material range over 

 part of the Furness district, and the country to the north and north- 

 west of Morecambe Bay. Most of this is in North Lancashire, but 

 a portion of it lies in Westmoreland. The Sheets 98 S.E., 98 S.W., 

 and 91 N.W. of the One-inch Map of the Geological Survey take in 

 neai'ly the whole of this region. 



The Carboniferous strata here represented are the Scar- or Mountain- 

 Limestone and the Yoredale rocks. A little further to the west, in 

 the valley of the Lune, the Millstone-grit and Coal-measures come 

 in ; but these we have not seen. The localities are therefore all iu 

 the lower half of the Carboniferous series. 



The Scar-limestone is about 1000 feet in thickness, and is finely 



