28b 



SCIENCE- GOSSIP. 



A New Species ok Slug. — In the current number 

 of the "Journal of Malacology" (vol. vii. No. 4, 

 p. 78), Mr. Collinge describes a new species of 

 Auadcuus from China recently received by the 

 British Museum. He calls it A. sechuenensis from 

 its locality, and gives a detailed account of its ana- 

 tomy ; but owing to the fact that so little is known 

 ar-out the structure of allied forms, it is impossible to 

 dwell much upon the affinities of this or the other 

 species of slugs he mentions. — W. M. Webb. 



Notes from Buckinghamshire. — One speci- 

 men of Bythinia tentaculata was found by us in the 

 upper reaches of the river Thames near Aylesbury, 

 Bucks, with a narrow opaque white spiral band ; the 

 shell was a full-grown one. A number of young 

 Physa fontinalis taken in the same spot we kept 

 for some time and watched. They were most lively 

 and were like a number of schoolboys who would not 

 leave one another alone. They appeared to be play- 

 ing together, and when their excitement reached its 

 highest pitch they let off their superfluous energy by 

 causing the shell to gyrate in a most peculiarly rapid 

 manner. — {Rev. ) E. Percy Blackburn. 



Mollusca in Intermittent STREAMS.--In 

 the summer of 1899 I found specimens of Aplc.xa 

 hypnorum, Limnaea percger, L. truncalula, Planor- 

 bis vortex, and a Pisidium too young for identifica- 

 tion on the top of Alconbury Hill, Hunts. They 

 occurred in a ditch in Cow Lane above Alconbury, 

 where the stream is intermittent, and sometimes the 

 ditch is quite dried up. L. percger also occurs in small 

 intermittent pools on the Abbott's Ripton road, an 

 ancient grass cattle- road. The above-named species 

 have therefore solved the problem of living in the 

 summer with an intermittent supply of moisture. 

 The specimens alluded to are not undersized. — {Rev.) 

 R. Ashington Bullen, F.L.S., Axeland, Horlcy. 



[When staying at Eton Wick during last summer 

 I found quite a number of fresh- water shells alive 

 and well, under the vegetable growth and refuse at 

 the bottom of a dried-up stream. Pisidium fonti- 

 nale was amongst them, and I have often noticed 

 that the smaller members of this genus occur in 

 positions that practically entitle them to be called 

 terrestrial bivalves. — W.M. W.] 



Rock-boring Helices. — It is stated, on the 

 authority of Bouchard-Chantereux, that the " mucoid 

 secretions " in Helix are acid in reaction and therefore 

 capable of eroding limestone rocks (J. W. Taylor, 

 " Monograph," p. 312). In a large number of 

 experiments on //. aspersa made some time ago, and 

 lately repeated, I found that the general foot and 

 mantle mucus, together with the blood and body 

 fluids as a whole, were distinctly alkaline to litmus ; 

 the contents of the gut on the other hand are, as a 

 rule, acid, and after discharges of fluid from this 

 source the snail might be able to claim that he 

 monies rumpit accto. If the general skin secretion 

 were acid, the calcium carbonate present in it would 

 keep the snail in a perpetual state of fizzing. — Arthur 

 E. Boycott, Oxford, January 12th, 190.. 



The Mollusca of Buckinghamshire Quite 



recently Mr. John R. B. Masefield has alluded to the 

 small number of molluscs recorded from Buckingham- 

 shire ("Journal of Conchology," vol. ix. p. 283). He 

 has only been able to find thirty-three species men- 

 tioned, and to these he adds five. All of these, with 

 the exception of C/ausilia laminata, were given 

 among the fifty which the writer was able to record 

 last year with the kind help of Mr. Lionel Adams 



(Appendix to the " Guide to Eton College Museum,' 

 June 1, 1899). The number has now been increased 

 to sixty, mainly by the addition of fresh-water species 

 which it was possible to collect in the dry weather of 

 last summer ; but it would be well if, as Mr. Masefield 

 suggests, the attention of collectors was turned to 

 Buckinghamshire, and one may add to Berkshire as 

 well.— Wilfred Mark Webb. 



Mounting Shells in Museums. — A propos of 

 Mr. Wilfred M. Webb's approval of Messrs. Boycott 

 & Bowell's remarks on mounting shells (S. G. for 

 Jan. p. 253), I would draw attention to a very 

 simple system for univalve marine shells, which I 

 saw in the Peabody Museum, Yale, in 1897. The 

 mount consisted of a solid wooden block, painted 

 or varnished, with a brass wire inserted centrally in 

 the block and proportionate to the length of the 

 shell mounted. The end of the wire was seemingly 

 bent for insertion in the mouth of the shell, which 

 was mounted in a perpendicular position. Great 

 economy of space was gained, every part of the shell 

 was available for inspection, and, I believe, could be 

 dismounted for closer examination — (Rev. ) R. Ash- 

 ington Bullen, F.L.S., F.G.S., Axe land, Ho r ley. 



Species of the Genus Limnaea. — In this 

 column for last month (S.G., ante, p. 253) the doubt- 

 ful differentiation of the forms we know as Limnaea 

 pereger and L. auricularia into separate species was 

 touched upon. Since the words in question were 

 written, Mr. George W. Chaster has published an 

 interesting note upon some hybrids, or, as he would 

 suggest, mongrels between Limnaea stagnalis ( $ ) and 

 L. auricularia ( ? ) (" Journal of Conchology," vol. ix. 

 pp. 282-3). The remarkable point about the obser- 

 vation is that the shells of the progeny which survived 

 are unmistakably those of Limnaea pereger. In this 

 Mr. Chaster sees a case of that reversion to ancestral 

 form which is known to occur as a result of crossing. 

 It seems somewhat of a pity that the specimens were 

 all killed, and that a series of experiments were not 

 made with them. Before, however, the full significance 

 of the likeness shown by the offspring of X. stagnalis 

 and L. auricularia to Z. pereger can be estimated, it 

 must be shown whether or no the pure -bred offspring 

 of the second species may not sometimes be indis- 

 tinguishable from the third. — Wilfred ALark Webb. 



The Colouring of some Essex Shells.— At 

 Tendring, Essex, there was a large colony of Helix 

 aspersa var. exalbida in our garden. The lack of 

 pigment was also very striking among Helix hortensis. 

 The bands on these shells were very frequently trans- 

 parent instead of being dark. A lack of pigment was 

 shared also by many plants, notably sweetbriar, 

 clover, docks, and brambles. Lady Rothschild's 

 head gardener at Ashton Clinton, Bucks, had 

 noticed the same thing there. He attributed it to 

 excess of iron in the soil. The well at Tendring was 

 decidedly impregnated with iron. We noted also 

 that during the great drought of 1896- 1897 the 

 markings on the shells of Helix asp, rsa were decidedly 

 deeper in colour, being in some cases almost black. 

 We had also a fine grape-vine in the garden, for which 

 these snails had a special weakness. The peculiarity 

 in their eating of the fruit lay in that they did not 

 attack one berry and finish it, but ate straight across the 

 bunch, so straight in fact that this looked as if it had 

 been cut with a razor. It may be worth while to 

 record a specimen of Llelix iiemora/is with a single- 

 black band with an opaque white beside it on a pink 

 ground. — (Rev.) E. Percy Blackburn. 





