1872.] MiCKINTOSH — CHESHIRE BOULDER-CLAY. 391 



Discovery of Sea -shells in the Lower Boulder -clay. 



For some time past the existence of sea-shells in the upper or 

 brick-clay of Cheshire and Lancashire has been well known to local 

 geologists ; but, with the exception of two species found by Mr. 

 De Ranee in the Lower Boulder-clay at Blackpool, I was not aware 

 that any shells might be dug out of solid parts of this clay, in a cliff- 

 section exhibiting a clear sequence of the two clays, until I visited 

 Dawpool* ; and I am not sure that the attention of geologists has 

 hitherto been specially directed to the fact tliat a thoroughly glacial 

 clay (as much so as many clays referred to the action of land-ice) 

 may contain not only numerous fragments of shells, but many nearly 

 perfect, and some, I believe, quite perfect specimens f. 



Appendix. — List of Shells from the Lower Boitlder-clat of 

 Dawpool. By J. Gwtn Jeffreys, Esq., F.E.S., F.G.S. 



Univalves. 



Littorina littorea ; fragment. 



Lacuna divaricata. 



Turritella terebra ; several fragments 



besides a nearly perfect specimen. 

 Purpura lapillus ; fragment. 

 Nassa reticulata ; fragment. 

 Buccinum undatum ; two fragments. 

 Fasus antiquus ; two fragments. 



In all, 15 species. 



Bivalves. 

 Leda pernula. 

 Cardium echinatum ; fragment. 



edule ; numerous fragments. 



Astarte borealis ; two fragments. 



sulcata, var. elliptica. 



Mactra solida. 



Scrobicularia alba ; fragment. 



Tellina balthica ; numerous fragments 



All these evidently come from a beach-deposit, and agree with 

 the Posttertiary shells from Moel Tryfan, the Severn valley, and 

 Macclesfield. One of the species (^Astarte borealis) is arctic or pecu- 

 liarly northern, and does not at present live in the British seas, 

 although it occurs in every Glacial and Postglacial bed. The most 

 southern locaUty for this sijecies, to my knowledge, is Kiel Bay in 

 the Baltic +. 



* I have since ascertained that a TurriteUa previously brouglit from Dawpool 

 by a very promising young geologist, Mr. W. Shone, jun., of Chester, was taken 

 by him out of the solid lower clay. 



f A number of the shells, including Turritella terebra, which I sentto Mr. S. V. 

 Wood, jun., and afterwards (in two lots) to Mr. Gwyn Jeffreys for inspection, 

 and which I dug out of parts (near the base) of the hard, .-stony, Lower Boulder- 

 clay cliifs at Dawpool, were almost perfect. 



I [Mr. Isaac Roberts, F.G-.S., of Eock Ferry, has found 18 species of shells in 

 the upper or brick-clay aroLmd Liverpool and Birkenhead (see ' Proceedings of 

 the Liverpool Geol. Soc' 1870-71); and Mr. Shrubsole, of Chester, has found 4 

 additional species in the same clay, making 22 species in all — namely, Turritella 

 terebra {communis), Gyprina islandica, Fusus islandicus, Aporrhais 'pes-'pelecani^ 

 Trophon clathratus, Tellina solidula ( Tellina balthica), Natica sp. , Nassa reticulata, 

 Purpura lapillus, Cardium edule, Cardium echinatum, Ostrea edidis, Pecten oper- 

 cularis, Littorina littorea, Lutraria sp., Mactra sp., Buccinum undatum, Dentalium 

 entalis, Murex erinaceus, Mytilus edidis, Lucina borealis, Psammobia ferroensis. 

 Five of the species I found in the lower clay at Dawpool do not appear in this 

 upper-clay list, namely Leda pernula, Astarte borealis, Astarte sulcata, Scrobi- 

 cidaria alba, and Fusus antiquus.— D. M.] 



