554 R. Ethericlge, Jun. — Glacial Deposits of Leivis. 



Here and there in the Upper Clay are to be seen sandy nests or 

 patches ; these are also fossil if erous, and from one of them I obtained 

 tolerably good specimens of Turritella terehra, and pieces of Cyprina 

 Islandica. 



Mr. Geikie has already pointed out the resemblance of the 

 Lewisian fossiliferous Boulder-clays to that of Caithness,^ and it now 

 only remains for me to add that of the twenty-two forms above 

 mentioned taken from the beds collectively sixteen are met with in 

 the Caithness Boulder-clay, one (Leda pernula) is represented by a 

 variety. Another, here a variety (Astarte compressa, var. striata), 

 is there represented by the typical form, whilst four (Mactra solida, 

 Fusufi gracilis, Astarte depressa, and Natica Montacuti) are not given 

 in Mr. C. W. Peach's list of Caithness fossils. Of the Foraminifera 

 one only (Truncatidina refulgens) is not mentioned by him.^ 



So far as I am aware, the Caithness deposit is the only one in 

 Scotland which has yielded Salicornaria, as I do not, at the present 

 moment, recollect any mention of its occurrence in the Clyde Valley 

 beds. Two fragments have turned up in the Lewis washings. On 

 looking over the foregoing list one or two interesting points may be 

 dwelt on. Dentalium entalis and Turritella terehra are of frequent 

 occurrence in the Lewis beds, although not generally abundant in 

 other Scotch Glacial deposits. The former of the two species appears 

 to be chiefly confined to the beds met with in the north of Scotland, 

 as Wick, Belhelvie, King Edward, and Gamrie;^ the latter is to be 

 found in Caithness, and at Gourock, and Auchleuchries.* Again, 

 Natica Montacuti, of which we obtained only one specimen, is said to 

 occur in Bute, in the Clyde beds;^ whilst Fusus gracilis has, so far 

 as I am aware, only been recorded from the Dalmuir deposit, by 

 Messrs. Crosskey and Eobertson,^ and in this case only the fry. The 

 single specimen (1 valve) of Astarte depressa. Brown, was deter- 

 mined for me by Dr. Gwyn Jeffreys, and is a peculiarly Arctic form. 

 Dr. Jeffreys appears to consider it identical with Astarte crebricostata, 

 Forbes," and under that name we have it recorded from Bute and 

 Dalmuir by the late Mr. James Smith.^ This, with Pecten Islandicus, 

 are the only two really Arctic shells in the list, although there are 

 several northern forms, as Leda pernula, Cyprina Islandica, Saxicava 

 Narvegica, Natica Montacuti, Fusus gracilis, etc. Such Arctic forms 

 as BhynclioneUa psittacea, Linn., Astarte borealis, Chem., Glycimeris 

 siliqua, Lamk., and Dentalium ahyssorum, Sars., which have been 

 found by Mr. C. W. Peach in the Caithness Boulder-clay, have yet to 

 be met with in the Lewisian deposits. 



[Note by Mr. Geilde. — *' My chief object in revisiting the north part 

 of Lewis was to re-examine the distribution and extent of the shelly 



1 Great Ice Age, p. 211. 



2 See C. W. Peach, Proc. Edin. Physical Soc. vol. iii. pp. 38 and 396. Brit. 

 Assoc. Ptep. for 1862, Trans, of Sections, p. 84; 1864, p. 62; and 1866, p. 65. 



2 Jamieson, Quart. Journ. Geol. Soc. vol. xxi. p. 198. 



* Prof. A. Geikie, Glacial Drift of Scot. p. 182. Jamieson, I.e. p. 199. 



^ Smith, Ptesearclies, p. 52. ^ Trans. Geol. Soc. Glasgow, vol. ii. p. 281. 



"^ British Conchologj^, vol ii. p. 320. 



^ Ptesearches, p. 47 ; and Crosskey and Eobertson, I.e. p. 274. 



