348 YORKSHIRE NATURALISTS’ UNION AT COXWOLD AND BYLAND. 
which, however, there was no stream. Here the first important 
discovery of the day was made, Mr. Roebuck finding /yalinia 
excavata under a stone, in company with H. rofundata and other 
species. So interesting a find caused careful and diligent turning 
over of stones along the whole ravine, with the result that the same 
collector was so fortunate as to find a fine example of that rarity, 
most conchologists unaccustomed to slugs in particular would have 
passed it by for Avion ater. However, a second glance revealed the 
light-coloured dorsal keel, and the identity was speedily confirmed 
by the characteristic trifasciated foot-sole. Nothing else turned up 
in this ravine, and the track was now across the moor to the S.W., 
and into another ravine of much greater depth, and with a rough 
stony bottom and its upper slopes crowned with wood, which 
trended towards Wass village. Despite the difficulty of picking 
one’s way down so rough a course, difficulty enhanced by the 
luxuriance and unusual virulence of the growth of nettles, ice 
was kept up, and rewarded by the capture of such species as He/ix 
lapicida, Azeca tridens, and numerous commoner things. 
Not far from the village of Wass, at the base of Hambleton Hills, 
an interesting pond was visited, which contained an abundance of 
Spherium lacustre and Pisidium fontinale, mostly of the variety 
cinerea, and an odd specimen of variety hens/owana was also taken 
from it. The pond was supplied by a stream descending the slope 
of the hill, and was singularly suggestive of the way freshwater 
deposits may be formed on a small scale. A very distinct deposit of 
a whitish clay was seen on the partially dried-up banks, which con- 
tained numerous shells throughout its whole thickness. A smaller 
pond by a farmhouse, which had a marshy outflow down the 
rugged hill-side, suggested during a brief halt that the Marsh Slug 
(Agriolimax levis) should be looked out for, and it was at once 
found. 
In the wood at the end of this road, all the time remaining at 
disposal was spent, and proved exceedingly productive, Azeca tridens 
occurring there in considerable numbers ; in fact, hardly a stone OF 
branch was overturned without observing some kind of mollusc upon 
it. Unhappily the party had not gone far before it was found necessary 
to retrace steps for want of time, and in consequence some of the 
most promising localities had to be skipped. Altogether were 
found 3 aquatic species and 33 terrestrial, but there can be little 
doubt that with further Recline pai this list will be materially 
increased. : 
Navoralist 
