259 



LIMAX CINEREONIGER, ITS VARIATION IN SAVERNAKE 

 FOREST, AND DESCRIPTION OF A NEW VARIETY. 



By W. DENISON ROEBUCK, M.Sc, F.L.S. 



(Read before the Society, October 13th, 1917). 



On the snd September, 191 7, My. Charles Oldham investigated Saver- 

 nake Forest in Wilts North with remarkable success as regards this 

 species, which was in great abundance and remarkable variation in 

 colour and markings. There were no less than eight distinct varieties, 

 named or nameable, in the consignment he sent me, and he remarked 

 that shortage of tins alone prevented him from doing more than select 

 the most conspicuous forms. One, a half-grown example of var. 

 cinereo-nebulosa, is a striking form which I have not seen before, and 

 which I have sent to the British Museum for permanent preservation. 

 There were two adults of var. strobeli, two adults of the well-known 

 var. hictuosa, a half-grown example of var. vet^a, very young specimens 

 of var. maura and var. efasciata, and there were also two forms which 

 cannot be identified with those described in Taylor's Monograph. 

 One has the markings of var. vera, and the other of var. intemtpta, but 

 in each case the colour is brown and not as in the descriptions of 

 those two forms. 



For these I propose a new variety as follows : — 



Limax cinereoniger var. brunnea nov. Colour brown, both 

 as to ground-colour and markings. 



This varietal name applies to colour only, and is applicable in con- 

 junction with any other varietal name. Thus in the present instance, 

 there were two examples, one very young, and one about a quarter- 

 grown, with the two bands of var. 2'era, and which are, therefore, var. 

 brufmea + vera ; and two, one half-grown and one a quarter-grown, 

 with the same two bands broken up into numerous elongated spots 

 and aspersions, the markings of var. i/iterrupta, and these are, there- 

 fore, var. brunnea -f interrupta. 



Some of the other slugs obtained by Mr. Oldham at the same time 

 are also interesting. Not to speak of the ordinary forms seen of 

 Agriolimax agrestis and Arioii hortensis, Limax ntaxinius was repre- 

 sented by its varieties cellaria, fasciata, obsciira, and ferussaci, L. 

 arborum by its type and var. hettonii, Arion ater by its varieties iivida, 

 plutnbeo-pallescens and brunneo-pallescens, and Arion subf incus by its 

 varieties rufo-fusca, cinereo-fusca, Sindfuliginea. 



Altogether this Savernake Forest consignment is a most remark- 

 able one, and speaks volumes for that locality as a collecting-ground. 



