29 



resembling a whirlwind in miniature, and ending with the complete 

 precipitation of the smoke. 



When the discharge takes place in Geissler tubes from which the air 

 or other gas has been partially exhausted between electrodes of platinum 

 or, better, aluminium, very beautiful effects are obtained in an almost end- 

 less variety, according to the forms of the tubes and the gases present in 

 them. 



July 10th, 1886. 



EXHIBITS. 



The concluding meeting of the session was devoted to the examina- 

 tion of a varied collection of natural history specimens and microscopical 

 objects. W. D. Eoebuck exhibited living examples of Limax cinereo- 

 niger, L. maximus, Arion ater var. rztfa, found on the east side 

 of Lindley Wood Reservoir, Washburndale ; and very fine and 

 characteristic specimens of Limax maximus from Leicestershire, Derby- 

 shire, and West Yorkshire, which showed the normal type of colour 

 and markings. The Limax cinereo-niger is an extremely rare slug, 

 and one which the exhibitor was the means of introducing definitely 

 into the British list. It is true that one was taken in Ireland about 

 forty years ago, and another in North Somersetshire about twenty 

 years ago ; but the naturalists who recorded them, though givino- 

 recognisable descriptions, took them to be abnormal examples of one 

 common species, L. maximus. The two species are very different from 

 each other, and can never be confounded on careful scrutiny. The rarity 

 can be judged from the fact that this is but the ninth British example, 

 six of which have passed through his hands. In its European distribution 

 it is a species which affects countries with a high average rainfall, so far 

 as is at present ascertained. Other exhibits were a number of Lepi- 

 doptera from Pateley Bridge, sent by W. Storey, including the female 

 of the Ghost Moth {Hepialiis humuU), the white Ermine Moth {Arctia 

 menthastri), the ruby Tiger Moth (Phragmatohia fuliginosa), the Burying 

 Beetle, and others. Miss F. A. Penistone exhibited a very good example 

 of the Tarantula, from Los Angeles, California, and a leaf of the Ficus 

 elastica. W. E. Collinge brought a collection of freshwater shells, taken 

 this season from the canal at Newlay, among which were Anodotita 

 cygnea, A. anatina, Unio piciorum, U. p. var. curvirostris, U. tumidus, 

 Dreissena polymorpha, Paludina vivipara, Bythinia tentaculata, Planorhia 

 vortex, Limnaa peregra, L. auricularia, Aneylus Jluviatilis, and Neritina 

 fiuviatilis. Chadwick showed eggs of Tree Sparrow, from Arthington, 

 white House Sparrow, Chiffchafi; Reed Warbler, and very small Sedge 

 Warbler ; and J. W. Dixon and E. Emsley brought a collection of 

 microscopical slides, including specimens of ripe eggs of Goby ( Gohius niger) 

 and young Starlet {Asterina gibhosa). 



