HARDWICKE'S SCIENCE-GOSSIP. 



43 



short intervening spaces. I await criticisms with 

 explanations annexed to them ; it is so easy to cut a 

 theory to pieces, but so difficult to build one. — 

 F. C. D. B. 



ZOOLOGY. 



MOLLUSCA IN the Ealing District. — This 

 neighbourhood is certainly one of the richest near 

 London in land and freshwater shells, and will well 

 repay a visit. As a proof of this, I append a list of 

 forty species taken in the course of a single walk on 

 April 26. — Sphccrium corneum, Planorbis corneus, 

 P. contortus, Physa fontinalis, Limtuea peregra, 

 v. ova/a and L. palustris : in the pond, "To be let 

 for building purposes " on the main road between 

 Acton and Ealing. All the molluscan inhabitants of 

 this pond, owing to favourable circumstances, reach 

 an unusual size. In the canal, on the contrary, 

 everything is more or less dwarfed and depauperated. 

 L. percgra v. acuminata ; in a pond near Ealing 

 Common. — Sj>/i. corneum, Anodonta anatina, Unio 

 pictorum, Paludina vivipara, Bythinia tentaculata, 

 B. Lcachii, Plancrbis alius, P. vortex, P. car hiatus, 

 P. corneus, Physa fontinalis, Lint, percgra, L. stagna- 

 lis, and L. palustris : in the Paddington Canal at 

 Twyford— Drcissena polymorplia and Sph. vivicola : 

 single valves in the Brent — Pisidium fontinale, 

 Planorbis nitidus, P. nautileus, P. vortex, P. corneus, 

 Limnma stagualis, L. peregra v. ovata, Ancylus lacus- 

 tris : associated in a large pond near the canal at 

 Twyford — Arion ater, A. hortensis, Limax lavis, 

 L. agrestis, Succinea clegans, Zonites cellar ius, Z. niti- 

 dulus, Z. nitidus, Z. crystallinus, PL aspcrsa, H. 

 nemoralis, H. hortensis, IP. Cantiana, H. hispida, 

 PL. concinna, LP. rufescens, H. rotundata, Cochlicopa 

 lubrica, Clausilia rugosa, and Carychium minimum. 

 Twyford and Ealing — One specimen of Physa 

 fontinalis had the lip tinged with pink, and two others 

 exhibited well-marked spinal bands, the first having 

 a single band near the periphery on the greater part 

 of the body whorl, and the second a similar, but 

 broader band at the periphery, and four distinct 

 lines close together in the place of the fourth band in 

 LL. nemoralis. — Sydney G. Cockerell, 51 Woodstock 

 Road, Bedford Park, W. 



Rotifer infested with Trichodina. — Mr. 

 F. B. Rosseter's paper in the December number of 

 the Royal Microscopical Society's Journal on Tricho- 

 dina induces me to record having found the same 

 Infusoria on two occasions on a rotifer Synclncta 

 pectinata. On the last occasion I carefully watched 

 for some time a Synchrcta infested with two Tricho- 

 dina; which were running in all directions over the 

 body and cilia of the Rotifer, and were not shaken 

 off by the sudden and violent contractions charac- 

 teristic of this species. The Trichodina on close 



examination could not be distinguished from T. 

 pediculus, parasitic on Hydra, as figured by Saville 

 Kent. The Rotifer seemed not to suffer in any way, 

 and as vigorous as the others free from Trichodina. 

 Synchreta's size is 7 ' n th inch, and Trichodina is j^th 

 inch in diameter, or about one-sixth the size of the 

 former, so that they were rather large parasites for 

 the little Rotifer to carry about with him. — Charles 

 Roussclct. 



Great Black-backed Gull. — On January 4th 

 one of these birds, probably driven inland by stress 

 of weather, settled on the vane at the top of the 

 spire of St. Marie's Church in the centre of this 

 town, and remained therefrom 10.30 A.M. until noon. 

 It was identified with the aid of a powerful telescope 

 by Mr. J. T. Webster, of the Museum Hotel. As 

 this spire is about 200 feet high, and the church 

 stands over 250 feet above sea level, the gull could 

 not have had a very warm perch. This is supposed to 

 be the first appearance of the great black-backed gull 

 in Sheffield. — Phomas I Finder, Sheffield. 



Occurrence of Limax cinereo-niger in 

 Sussex. — Last August I obtained three specimens 

 of this slug at Up Park, near Harting, in the extreme 

 north-west corner of the county. Two were sent for 

 identification to the Conchological Society, Leeds, 

 and one of these turned out to be the variety Ornati. 

 I have also lately met with the following slugs in 

 West Sussex, which have not hitherto been mentioned 

 in the local lists, viz. Arion subfuscus, Arion bour- 

 guiguati, and Limax Levis. — William Jeffery. 



The Little Bustard in West Sussex. — I have 

 just seen a specimen of this bird which was killed 

 by Mr. Coote, of Clymping (Arundel district), towards 

 the end of last year. A little bustard was killed 

 some years ago at Bosham (Chichester district), by 

 Mr. A. Cheesman. This was just prior to the 

 publication of Knox's " Ornithological Rambles " 

 in 1855, and is there noted. — William Jeffery. 



Axinus Croulinensis.— At the last meeting of 

 the Glasgow Natural History Society, Mr. A. Somer- 

 ville, B.Sc, F.L.S., exhibited specimens of Axinus 

 Croulinensis, one of the smallest and most interesting 

 of British marine bivalve shells. This mollusc was 

 discovered forty years ago by Dr. Jeffreys off the 

 island of Croulin, and has been taken by Canon 

 Norman in Shetland waters, and in various of the 

 Norwegian fiords. But since its discovery by Jeffreys, 

 it is not known to have been taken in what may 

 properly be termed British waters, until dredged by 

 Mr. Somerville last August in about thirty fathoms 

 water in Gairloch, Ross-shire, and alsD in Loch Broom. 

 Specimens of the other two British species of the 

 genus Axinus were shown for comparison, also an 

 enlarged diagram illustrating the minute characteris- 

 tics by which the species are distinguished. 



