400 A. F. Griffith — Find of a Flint Implement in Gravel. 



It may be mentioned that although attempts have been made 

 to classify the Irish Silurians similarly to those of England, yet 

 it is not a satisfactory classification, as the fossils of the English 

 groups are mixed up together in the Irish ones ; this is a subject 

 •which if fully entered into would take up too much space, but it may 

 be mentioned that in the Kerry, Galway, and Mayo Silurians there 

 is a thin zone, at about the same geological horizon, which carries 

 Cambro-Silurian (Caradoc) fossils, while in the rocks below and 

 above they are of Upper Llandovery and Wenlock types. In one 

 portion of Galway there are at least 3000 feet in thickness of Upper 

 Llandovery rocks below this zone. I would suggest that the 

 American and Continental Silurians in which Land Plants occur 

 are possibly equivalents of the Irish groups to which I now draw 

 attention. 



Note. — Prof. Claypole has described a Lepidodendroid plant, Glyptodendron 

 Batonense, from tlie Upper Silurian (Clinton) rocks of Ohio, in the American Journal 

 of Science for April, 1878, p. 302.— J. M. 



IV. — On a Flint Implement from the Baenwkll Gravel. 

 By A. F. Griffith, Esq. 



AEEW weeks ago a flint implement was found in the gravel-pit 

 at Barnwell, near Cambridge, by the workmen, from whom 

 I bought it. It is a very fine specimen of the hache type, 

 its greatest length being 6f ins., its greatest breadth 3f ins., and 

 thickness 2|-. It corresponds closely with specimens in the Wood- 

 wardian Museum, from Thetford, in Sufi"olk, and from Amiens. It 

 agrees almost exactly in size and outline with an implement of the 

 " Eiver-drift type," figured by Dr. John Evans in his beautiful work 

 on the " Ancient Stone Implements of Great Britain "; from Bidden- 

 ham, Bedford (fig. 414, p. 481) ; also with one from Eedhill, 

 Thetford (fig. 427, l nat. size, p. 496, op. cit). 



The pit where it was found is in the well-known Barnwell river 

 gravel, which contains a considerable number of bones of Mammalia, 

 including those of Bos, Eqims, Cervus, Bhinoceros ticliorJiinus, 

 Elephas primigenius and antiquus, and Hippopotamus,^ and has in 

 places a thin band of shells, amongst which Unio littoralis and Cyrena 

 flmninalis are common. This band, however, is not found in the 

 present pit, though it occurred in the old pit about 350 yards 

 distant, on the side of the Newmarket Eoad, which was in the same 

 gravel, and is on the same level as the present one. The occurrence 

 of a worked flint associated with these shells is, I believe, very 

 unusual. At Menchecourt, in France, Cyrena Jluminalis was found 

 by Prof. Prestwich, in the implement-bearing gravel, while I only 

 know of one instance having been recorded of a worked flint having 

 been found associated with Unio littoralis ; this was found in the 

 brick-earlh of Crayford, Kent, by Mr. Fisher, in 1872.^ 



The only other evidence of man's existence which has hitherto 

 been obtained from this deposit is perhaps of a rather doubtful 



1 Quart. Journ. Geol. Soc, vol. xxii. p. 476. 



2 Geol. Mag. June, 1872. 



