LAMPLUGH : GLACIAL BEDS. 
177 
that the " Basement" and " Purple" clays have their greatest 
development in Holderness, whilst the " Purple " and 
" Brown " predominate north of Flambro', — the Hessle 
capping all. 
There is no space within the limits of the present Paper 
to point out the important bearing of some of these facts 
on the several theories advanced as to the mode of formation 
of these clays, but I hope on some future occasion to be able 
to do so. 
THE SOUBOE OF THE RIVER AIRE. BY THOMAS TATE, F.G.S. 
" Arus ex Pennigenti montibus radicibus ortis." * This 
was the opinion of the great topographer, Camden, the 
earliest on record. 
Hurtley, the Malham schoolmaster, writing of Malham 
Water — "a lake embosomed in the cloud-capt mountains" — 
describes it as " the fountain of the river Air, which, hiding 
itself, as it were, immediately on its escape from its parent's 
confines, traverses the bowels and cavities of the earth till it 
finds a snug and secure retreat amid the almost inaccessible 
crags at the foot of the Cove." f 
The relative claims of the different feeders are fully dis- 
cussed by Whitaker : — " Speaking in general terms, the lake 
may fairly be considered as the source of the Aire ; but 
as its outlet quickly sinks into the ground, and is lost, and 
as several streams which appear below contend for the honour 
of the connection, it still remains a matter of some un- 
certainty to which of them the preference is to be given. 
* " Britannia," 1st ed. (1590), page 559. " Leland saith it riseth neere 
unto Orton in Craven," Harrison (1577) " Description of Britaine." This is 
mere hearsay, Leland never having visited the district. The quotation is 
unaccompanied by any reference, and I have not been able to meet with it in 
the " Itinerary." 
t " Natural Curiosities of Malham " (1786), page 31. 
