W. Swanston — Clays overlying Basalt, Lough Neagh. 63 



regarding their character, and the age of the containing beds, that 

 he concludes his paper by remarking, in the absence of better speci- 

 mens, that, " In the meantime it is right to place the matter on 

 record — seeing that this place is, so far as I know of, the only- 

 locality in the British Isles yielding lacustrine fauna of Pliocene date." 



During the past summer, in company with a few other amateurs, 

 I made frequent visits to the Crumlin Kiver, and succeeded in pro- 

 curing better examples from the same clay beds than had apparently 

 been obtained before. As the opinion formed from the inspection of 

 the fossils on the spot, and from other independent evidence, is 

 entirely different from the conclusions arrived at by Mr. Hardman, 

 not only as regards the shells, but also respecting the age of the 

 beds ; and as considerable importance has been attached to the 

 determination of the shells as indicative of a Pliocene lacustrine 

 fauna in Britain ; I had a good series of them prepared and sent to 

 Dr. J. Gwyn Jeffreys, F.R.S., for his opinion regarding them. 

 That gentleman, with his usual kindness, states, " I can come to no 

 other conclusion than that they are certainly not any species of Unio, 

 but belong to our common mussel (My til us edulis). 1 which occurs in 

 all the newer tertiaries. The structure, composition and colour 

 agree (See British Conchology, vol. ii. p. 103.)" 



A quantity of the material from the same shell-bed was submitted 

 to Joseph Wright, Esq., F.G.S., of Belfast, for microscopic exami- 

 nation. Mr. Wright reported that the only microzoa that he was 

 able to detect in the clay were a few foraminifera, referable to four 

 species, namely : — 



Globigerina bulloides, D'Orb. — very rare. 

 Textularia variabilis, Will. — small, and very rare. 

 Discorbina globularis, D'Orb. — rare. 

 Nonionina depressula, W. and J. — common. 



The foraminifera above enumerated are all found living and in 

 abundance on our coasts, and are also species which are of frequent 

 occurrence in our Drift-beds ; the last mentioned, especially, is a 

 very common Boulder-clay form. 



The coarse material left after the examination for microzoa, consists 

 for the most part of small round pieces of clay, which were too hard 

 to dissolve in the washing. There were also a good many fragments 

 of lignite, and one piece of silicified wood about an inch in length. 



An examination of the stratigraphical position of these fossiliferous 

 clay-beds proves that they repose upon a deposit of true Boulder- 

 clay, the position of which is accurately represented in the section 

 illustrating Mr. Hardman's paper, 2 and is there described as follows : 

 " m. Coarse gravelly clay — pebbles of quartz and basalt — resting in 

 pockets and erosions of basalt = 3 feet." This coarse gravelly clay 

 is of a dark brown colour, extremely compact, and full of large 



1 This confirms the opinion expressed by the Editor of the Geol. Mag., that the 

 fossils shown him by Mr. Hardman indicate rather a Mytilus or Modiola-like shell 

 than a Unto. — See Geol. Mag., December, 1876, foot-note, p. 557. 



2 Geol. Mag. 1876, Decade II. Vol. III. PI. XXII. Fig. 1 ; and Joum. Eoyal 

 Geol. Soc. of Ireland, vol. iv. part iii. new series, pi. xii. fig. 1, etc. 



