1 8 Gibbs : Yorkshire Naturalists' Union at Masham. 



at Healey and at Swinton, numerous H. rotundata at the latter 

 village, and a very young example of Limax maximns under 

 the bark of an oak log" at Swinton. Messrs. C. Crossland, F. L. S. , 

 and Mr. Thomas Gibbs brought from the Hall Wood Hyalinia 

 crystallina, H. alliaria (young), a pale greenish-white juvenile 

 specimen of Arion ater, and a very small example of Limax 

 marginatus (arboruni) of typical markings but very dark. The 

 last-named was of considerable interest in that from it emerged 

 an extremely long thread-worm, evidently a parasite. 



Mr. Roebuck next visited Marfield Pond under the guidance 

 of Mr. J. J. Burton, who had visited the place the previous 

 day, a fine large sheet of water, overgrown in the centre with 

 vegetation, and its muddy verge so trodden down by cattle as 

 to render it difficult to get to collect in the clear water which 

 stood between the reeds and the edge. Here were found 

 Li?n?icEa stagnalis in great abundance and very large and fine, 

 several L. pain sir is, Planorbis corneus in great abundance and of 

 ordinary size, PI. complanatns in great plenty and exceedingly 

 fine, some of the specimens being as large as Mr. Nelson has 

 seen, and Bythinia tentaculata, also in great plenty, besides 

 a few examples of a Pisidinni which were lost before they 

 could be specifically identified. Most of the shells were covered 

 with confervoid vegetation, except those collected at one or 

 two points where it was evident the pond was fed by springs. 



The total list thus amounted to twenty-one species and one 

 albino variety — eight species being freshwater, eight land snails, 

 and five slugs. 



The Entomologists were solely represented by Mr. G. T. 

 Porritt, F. L.S., and Bank Holiday train exigencies unfortunately 

 prevented him from having more than a short afternoon's work ; 

 his report shows w 7 hat good use he made of this short time; 

 he says that the Entomologists were exceptionally fortunate. 

 In a district almost unworked, containing so much water, it 

 was natural that the Trichoptera should be in full force, and 

 in less than two hours' work on the river Ure, in adverse 

 weather conditions, Mr. G. T. Porritt succeeded in securing 

 no less than five species hitherto unrecorded for Yorkshire, 

 two of them being quite common ; indeed one of them in 

 great abundance. The new species w r ere : — 



Lepidostoma hirta, common. 



Leptocerus albifrons. 



Neu reel ipsis bimaculata. 



Naturalist 



