SCIENCE-GOSS/J' 



95" 



MOLLUSCA 



v^^JCCK 



CONOl'CTKU BY WII.l'-REI) MAKK WKBB, K. L.S. 



IMk. Wii.i'rkp M,\rk W'mhii. I'.L.S., lately Kditor oC the 

 "JournnI of M>il:ii.*iiKif;y. " han kindly uiiilLTtakcn to conduct 

 the columns devoted to MolUisca. in SciKNCl-:-CiOssil*.— 



Arf. .v-<;.; 



liEl.lX I'OMAI lA I.N Km'.I.AM). — Al il rccciu 

 iiieftiny of the- Maliiculoyical Sociely the Rev. 

 Ashingloii BuUen, K.G.S., yave an account of a 

 llolocene deposit M Kcigate. The hills near Keifjate 

 are well known a^ one of the stronglioMs of //rlix 

 I'ontatiii^ a species said to have been introduced into 

 this spot from Italy al the beginning of the century 

 l)y an Knglish nobleman, as a cure for consumptioit. 

 It was thought by Colonel (iodwin- Austen that some 

 evidence as lo the lime during which our largest snail 

 has inhabited the country might be forthcoming from 

 the geological deposit alluded to, and it was carefully 

 examined by Mr. Hullcn. The result was that shells 

 of Helix poiiiatiii were discovered down to a depth of 

 j feet 6 inches, and below a neolithic flint scraper 

 with undamaged edge. This points to the fact tliat 

 the snail was al Keigate before Roman times though 

 no other evidence exists that it was an English shell 

 during the Roman occupation even in spite of the 

 name " Roman" which still clings to it. The fact 

 that Ihtix liitoniiii, a nearly-allied species, is its 

 Italian representative, though militating against the 

 idea that Hcli.r f'onuilia came at any time fioni Italy, 

 is haidly an argument against the idea that the 

 Romans brought the latter animal into this country. 

 The Romans appreciated large snails as a delicacy 

 like the French do now, and it would be 

 decidedly easier then, if not now, to bring 

 a supply from France than from Italy. It still 

 remains that no shells of the snail which I am 

 considering have been found in the Roman Rubbish 

 I leaps, and the flint weapon at Reigate may have been 

 washed into its present position in comparatively 

 recent years. Hence, \i Ht'lix poinatia is not to be 

 considered indigenous or a relic of Roman appetites, 

 we must find some new explanation, and probably in 

 such case the introduction was made from a 

 gastronomic point of view. It would be interesting to 

 know whether the monks of old, who looked so well 

 after their " inner man," shared the liking of Ben 

 Jonson for the ** .\pple" snail. I have before men- 

 tioned a runuiur, when recording the only locality 

 for this mollusc in ICssex, which is near the site of an 

 old priory, that the monks introduced it into the 

 country. — W'ilfnd Mark II 'c/i/i. 



I'KoiEcnvr. Resemhi.anck in Clausii.iak.— 

 Mr. Boycott not long ago coUecled a number of facts 

 in Sci KM K-< lossi r (S. -G. , X.S., Vol. iv. , p. i6i , etc. ), 

 which bear upon the variation and colouration of our 

 non-marine mollusca. In discussing these he throws 

 a doubt upon ihe theory .suggested by Mr. Miller 

 Christy (I'roc. Fs.sex Field Club, \'ol. iii., p. 92), with 

 regard to some Clausiliae, and by the present writer 

 (S. -G., N..S. , \'ol. ii., p. 227) in connection with 

 another species — namely that ihe spiral shells of these 

 species imitate in appearance the shrivelled bud-scales 

 of the trees in their habitats. Biologists are often 



accused of seeing wli&t other people cannot, but thi.n 

 is equally applicable lo the exponents of art, as 

 instanced by the tale of Turner, who when some 

 ' ritic slateil that he had never .seen in Nature such a 

 sunset as the great master had gxiinted, answered 

 dimply, " Don't you svish you could." Again, a 

 naturalist is sometimes met by an insinuation from hi< 

 fellows, that he sees what he hopes, or wants to sec, 

 and it is true that there is a need of caution when a 

 worker is wrapped up in his subject, lest he should 

 unwittingly tnagnify small points to the advantage of 

 his own theory and the detriment of another's. The 

 inlerpretallon of the uses of colour and form to 

 living beings is specially open lo criticism of this 

 kind, as evidence in proof of a particular explanation, 

 where it is possible to obtain any, can only be 

 produced after long and careful collecting of facts. 

 No fresh point can be raised at present with regard 

 to the ca.se of the Clausiliae, but Mr. Boycott gives a 

 reason for his duubts, and one WDuId fain criticise 

 this. lie says that if it be a genuine case " one would 

 expect to find Claiisi/la habitually living in situations 

 where it would be among the objects, lo which il has 

 a resemblance" (S. -CJ., Vol. v., p. 227). In conlrasl 

 to this and a previous statement that the species with 

 the exception of C iv/p/iii " are not very geophilloti.s," 

 the following little table is presented, showing habitats 

 noted among those given in their books on land and 

 freshwater shells by half-a-dozen authorities upon the 

 subject taken at random. 



Author. 



C fans ilia 

 biplicata. 



Claiisilta 

 laminata. 



Claxtsilia 

 rolphii. 



Clausilia 

 bidentata. 



Gray. 



Woods 

 and hedges 



Decayed 



leaves. 



Moss and 

 stones. 



Under 

 stones. 



Gwvn 

 Jcflfcrys. 



Roots of 



old willow 



trees. 



Roots of 

 trees, 



dead leaves 



L'ndcr 



stones and 



de;id leaves. 



Under 

 stones. 



Lavell 

 Reeve. 



Roots of 

 shrubs. 



Decayed 

 leaves. 



Dead 

 leaves. 



Under 

 stones. 



Tate. 



Under 



largcosicrs 



On trunks 

 of trees 

 after rain. 



Ri^otsofivy, 



decaylng- 

 leaves. 



Under 



stones. 



Rimmer. 



Lionel 

 Adams. 



Roots of 



willow 



trees and 



moss. 



Roots of 

 willows. 



Dead 



leaves, on 



fallea 

 branches. 



Roots of 

 trees. 



Under 



stones. 



moss, dead 



leaves. 



Under 

 stones. 



Under 



stones, L "acr 

 almost sub- stones and 

 tcrranean. "i^^^s- 



This ma)' show either how easy it is for one's 

 own uncorroborated observations to lead one astray, 

 or ht)W writers can perpetuate a mistake. Taking 

 however into consideration that Clausiliae are 

 .so widely spread, it is not likely that the authors 

 went outside their own experience for infor- 

 mation as to the habitat. That the ground is a 

 favourite s|X)t for Clausiliae is the unanitiious verdict, 

 and in many cases w here these snails are found on 

 tree trunks, they have crawled up from below after rain, 

 such occurrences being mentioned ;is a guide to ea.sy 

 collecting. I have found any number of C. hiflicata 

 upon the ground, and often mistook bud-sheaths for 

 shells. \\'hile in the localil\- for t". rolphii, which I 

 discovered in Surrey (S.-G., June, 1S77), I came 

 across this and the two other species within a square 

 foot of .soil .surface. — Wilfred Mark Webb. 



