342 THE ZOOLOGIST. 
plains of Italy the type-form is prevalent, but, just as in Waterford, the 
dark variety is only found high up on the mountains, ascending to nearly 
8200 feet. The other instance is that of L. maximus in the South of 
England. Mr. J. H. James has carefully searched Truro for varieties of 
this slug, and it is remarkable that all he has found there were distinctly 
spotted or striped with black or dark grey. These forms, so common in 
Cornwall, are either rare or absent in the colder Thames Valley, all our 
examples being dull and ill-marked, the almost unicoloured variety pre- 
vailing. Similarly, in the case of Arion ater, the variety in which the 
colours are distinct and well-defined, occurs at Truro, near Clonmel, and in 
various other localities in the south-west, but seems to be entirely absent 
in the Thames Valley.—T. D. A. Cockrrext (Bedford Park, Chiswick). 
SCIENTIFIC SOCIETIES. 
ZooLoGicaL Society oF Lonpon. 
June 29, 1886.—Ospert Satvin, Esq., F.R.S., Vice-President, in the 
chair. 
The Secretary exhibited, on behalf of Mr.John Brazier, of Sydney, 
New South Wales, a series of eggs of the Pacific Porphyrio, Porphyrio 
vitiensis ; and read a note showing the extraordinary fecundity of an 
individual of this species, which had laid in seven years 491 eggs. 
The Secretary read a letter addressed to him by Capt. Vipan, giving 
particulars of the nesting of a South-American Siluroid Fish, Callichthys 
littoralis, in his aquarium. 
A communication was read from Mr. Gilbert C. Bourne, containing 
general observations on the fauna of Diego Garcia, the southernmost island 
of the Chagos Group, situated in the centre of the Indian Ocean. 
Mr. Howard Saunders read a paper containing a description of the 
collection of birds obtained by Mr. Gilbert C. Bourne on the island of 
Diego Garcia. The species represented in the collection were stated to be 
fourteen in number, of which one only was a land-bird (introduced), the 
remainder being oceanic birds or migrants of wide distribution. 
Mr. J. Bland Sutton read a paper on the intervertebral disk between 
the odontoid process and the centrum of the axis in man. 
Prof. R. Ramsay Wright gave an account of Sphyranura Osleri, a 
recently-discovered ectoparasitic Trematode, intermediate between Gyrodac- 
tylus and Palystomum, which infests the gills and skin of Menobranchus. 
A communication was read from Mr. Gervase F. Mathew, R.N., con- 
taining descriptions of a new genus and some new species of Rhopalocera 
which he had obtained during a recent visit to the Solomon Islands. 
