452 Alfred Bell — Post-glacial Drifts of Ireland. 



Wexford fossils of species no longer living in British waters : — 

 (Northern forms) Astarte horealis, Lecla hyperhorea, Leda ohlonga, 

 Nucula proxima, Natica affinis, Pleurotoma Vahlii? Scalaria Groen- 

 landica, Trophon Fabricii, T. clathratus, Volumitra sp. {Groenlandica?) 

 (Southern forms) Zeda pusio ? Fusus crispus ? Nassa semistriata, 

 Turritella incrassata. (Japanese) Nticula Cohholdice. Habitat un- 

 known, Melampus pyramidalis, Fttsus Bailyi (n. sp.).^ 



For further comparison I append a list of all the shells known in 

 the Dublin drifts, 33 in number, that the divergence of the Eaunas 

 may be more readily understood. 



Still living in British waters : — AporrJiais pes-pelicani, Buccinum 

 nndatwn, Dentalium entale, Fusus antiquus, Littorina littorea, L. litto- 

 ralis, Nassa incrassata, N. pygmea, Natica Alderi, Trochus umbilicatus, 

 T. zizipliinus, Turritella terebra, Pleurotoma rufa, Astarte elliptica, 

 Cardium edule, G. exiguum, G. tuberculatum, Gorbula gibba, Gyprina 

 islandica, Ostrea edulis, Pecten opercularis, P. varius, Psammobia 

 ferroensis, P. vespertina, Pholas dactylus, Tapes decussata, Tellina 

 balthica, Venus gallina, V. verrucosa. 



(Extra British) Pleurotoma pryramidalis, Leda oblonga. (Possibly 

 British) Loripes divaricatus, and Woodia digitaria.^ 



To these may be added the extra British forms in the West of 

 England drifts : — Astarte borealis, A. crebricostata, Tellina proxima, 

 Natica affinis, Troplion clathratum. 



Altogether 9 extra British forms, 7 northern, and 2 southern ; 

 4 only out of the 9 being present in the Wexford deposits. We have, 

 therefore, 18 extra British species separating the two Faunas, a large 

 proportion out of less than 100 species all told. 



The Belfast species not included in the above lists are : — 

 Buccinum fusiforme f Astarte sulcata, 



Emarginula fissura, „ compressa, 



Fusus contrarius., Cardium echinatum, 



„ gracilis, ,, nodosum, 



Murex erinaceus, Mactra elliptica, 



Nassa reticulata^ „ truncata, 



Natica affinis, Mytilus edidis, 



Purpura lapillus, Nucula nucleus, 



Trochus tumidus, Pecten maximus, 



Trophon truncatus, Pectunculus glycimeris, 



Area lactea, Saxicava arctica, 



Venus ovata. 

 I do not attach much value to the separation of clays by sands, 

 (the arrangement of the Post-glacial drifts in Dublin Co. and in the 

 West of England) when unsupported by other evidence, and the 

 reader is referred to tbe papers by Messrs. Harkness, Hull, and 

 others, published in this Magazine, for full particulars upon these 

 heads. 



1 I merely indicate the existence of a shell from these gravels differing from any 

 species known, fossil or recent. It will be described and figured shortly. 



2 Prof. Forbes adds in his list in the Mem. Geol. Survey Nassa granulata from 

 Killiney. 1 venture to think this is an error. 



