412 MR. G. W. LAMrLUGH OX THE 



Fossils of the Speeton Shell-hed *. 



Tellina hcdfhica, L. 

 Scrohiadaria piperata, Gm. 

 Carclium edule, L. 

 Mi/tilus cdtilis, L. 

 Liftorina liitorea, L. 



riidis, var., Maton. 



Hydrohia ulvcB, Pen, 



Utriculus obtusns, Mont., var. perfenuis. 



There is nothing in cither of these lists to afford more than an 

 approximate idea of the age of the beds. I believe all the species 

 contained in them date back to pre-Glacial times, but are also all 

 present in later beds, and the collection is such as might occur 

 anywhere between the commencement and the close of the Glacial 

 period. The mammals found at Sewerby do not include any of the 

 characteristic pre-Glacial species of the Norfolk " Forest-bed series," 

 and bear a closer resemblance to those which occur in some " inter- 

 Glacial" localities t ; but as the ice itself could not bring the fauna, 

 and the species must have been in existence somewhere throughout 

 the Glacial period, this does not count for much. It is essentially 

 the fauna of the Kirkdale Cave, which was considered by Phillips + 

 to be pre-Glacial. The presence of TeU'ina halthica in abundance at 

 Speeton, on the other hand, shows that the beds were laid down in a 

 period not far removed from Glacial times. 



The evidence other than that of the fauna is also somewhat con- 

 flicting and uncertain. Along with the chalk pebbles in the Sewerby 

 Beach there are a few foreigners which, though their proportion to 

 the local rock is infinitesimally low, are yet of such diverse and far 

 distant origin that they can scarcely have reached this shore except 

 by the help of ice in some form or other. I collected these pebbles 

 during an excavation of the beds, and have compiled the following 

 list to show their character : — 



Pebbles in the Sewerby Beach §. 



Per cent. 

 Carbonaceous Shale of uncertain origin ... about 10 



Sandstone of various kinds ,, 25 



Quartzite „ 20 



Pah\?ozoic (?) Conglomerate ,, 3 



Vein-quartz ,, 4 



Basalticrocks ,, 17 



Felsitic Porphyry, &c „ 13 



Granite ,, 2 



Oolitic Limestone ,, 4 



Black and yellow Flint (not local) ,, 2 



100 



* These are the species in my own collection (see Geol. Mag. (1881) p. 177). 

 I have recently seen in the collection of Mr. R. S. Herries a brachiopod, 

 lihyitchoncUa psittacca, Chemn., from this bed. 



t Tiie elephant-remains, liowever, from the gravels of Holderness which lie 

 between the two Boulder-clays appear generally to belong to E/epha.i prhni(je7ih(s, 

 while all which have yet been found at Sewerby have been determined as E. an- 

 tiqv7(S, and this seems to indicate a certain degree of change in the fauna of the 

 locality in the interval covered by the Basement Clay. 



X ' (jeol. of Yorks.' 3rd ed. pt. i. p. 1G9. § See Brit. Assoc. Eep. quoted above. 



