LIMAX TENELLUS IN SCOTLAND 219 



It is, too, a great satisfaction that it has turned up in 

 the very part of the kingdom that I have confidently 

 expected it to do, the remoter and more primitive fastnesses 

 into which this, evidently a retreating and decreasing 

 species, has been driven by the pressure of the more domin- 

 ant forms of molluscan life which have appropriated the 

 more desirable districts and habitats. 



Mr. Godfrey's description of its haunts coincides very 

 closely with what we know of its characteristic habitats in 

 Germany. He states that its chief haunts are on old pine 

 branches lying half-smothered in the masses of blaeberries, 

 whortleberries, and heather. These branches are covered 

 with decayed pine-needles and other rotten vegetation, 

 amongst which the slugs are concealed. Several examples 

 were also found under stones. Its companions are Liinax 

 cinereo-niger in its varieties uiaura and luctuosa, and L. 

 arbonnn in its typical form but dark in colour, and its 

 montane var. alpestris, as well as Arion subfuscus and A. 

 minimus, specimens of all which I have seen and named, 

 but Mr. Godfrey states that L. tcnellus outnumbers them all, 

 just as it does in the German forests, as stated in Taylor's 

 Monograph. 



The surprise is that, considering how dominant a species 

 it is at Rothiemurchus, it should have escaped detection 

 by British conchologists all these years. 



But it is quite possible that the apparent scarcity of 

 both this species and of L. cinereo-niger is the consequence 

 of the superficial resemblance which each has to a very 

 different slug, which causes them to be overlooked by 

 observers who do not carefully note the generic character. 

 L. cinereo-niger in its totally black form, var. viaura, looks 

 very like the typical form of the common Arion atcr, and in 

 like manner the general external appearance of L. tenellus 

 as to colour and markings is very much that of Arion 

 subfuscus. 



This discovery will give an incentive to Scottish con- 

 chologists to examine other forests of similar character, such 

 as the Athole forests, and to search the peaty and heathy 

 tracts which have hitherto been shunned as unproductive of 

 molluscan life. 



