HERTFORDSHIRE NATURAL HISTORY SOCIETY. 
XXV11 
mansworth was commenced where a cutting is being made through 
the south-western corner of the Common. 
The route was now entirely along the new railway-line. An 
immense “pipe” in the Chalk first attracted attention, and the 
Director showed the identity of such pipes with swallow-holes, the 
chalk originally in them having been gradually dissolved and carried 
away by water holding carbonic acid in solution, and its place 
having been taken by the insoluble portions of the superincumbent 
strata, in this case chiefly sand and flint-pebbles. The probable 
origin of the dry valley before mentioned, part of which was now 
to be traversed, was then touched upon, and it was shown that the 
valley could be accounted for if the water-level in the Chalk had 
been in former times a little higher than it is now, when water 
would have flowed on the surface of the ground, instead of, as at 
present, only through the pervious chalk underground. This dry 
valley has been taken advantage of in the construction of the new 
line, which would without it have been a continuous cutting from 
Rickmansworth to Chorley Wood Common. 
In the course of the return walk two deep cuttings were passed 
through, showing sections, about 90 feet in height, of the Upper 
Chalk entirely free from “pipes,” owing to clay being on the 
surface and forming an impermeable capping, instead of gravel or 
sand which allow water to percolate through them. 
On arrival at Rickmansworth the members of the two Societies 
had tea and then dispersed to their several destinations. The 
party numbered forty. 
Ordinary Meeting, 27th November, 1888, at Watford. 
Professor Attfield, Ph.D., F.R.S., etc., Vice-President, in the Chair. 
The Chairman spoke of the great loss the Society had sustained 
by the recent death of Mr. John E. Littleboy, and of the valuable 
services he had rendered to the Society. 
Mr. J. E. Daw, Elmhurst, Watford ; Mr. T. Earries, 30, Clarendon 
Road, Watford; Mr. Sydney T. Klein, E.L.S., E.R.A.S., E.E.S., 
The Red House, Stanmore ; and Mr. J. M. McLarty, Market Place, 
St. Albans, were proposed as Members of the Society. 
The following lecture was delivered :— 
“ Rattlesnakes.” Ry Arthur Stradling, C.M.Z.S. 
The lecture was illustrated by living specimens. 
Ordinary Meeting, 27th November, 1888, at Hertford. 
F. M. Campbell, Esq., F.L.S., F.Z.S., President, in the Chair. 
The President exhibited a moth, captured at Bull’s Cross, near 
Waltham, which had been identified as the Alpine moth (Setina 
aurita , Linn.), but which he suggested might be merely a variety 
of the common dew moth (S. irronella } Aspa). 
