402 



as the Limax fuscus of Müller and Linnaeus, and he may by a very slight 

 slip have entered it as y)Arion fuscus Müll.« instead of ))Arionfuscusi- 

 Moquin Tandon or Ario)i Jwrtensis Fér. or Limax fuscus Müll. To his 

 addition »Probably introduced« some objection might be taken on the 

 ground that there is no very strong a priori reason, why an Arion 

 should not çxist in Greenland considering that it exists in Iceland, the 

 land shells of which Mörch himself (see Manual, p. 135) allows are 

 nearly allied to those of Greenland: and that it is not only an acknow- 

 ledged 1 member of the Circumpolar Fauna, but the most abundant of 

 all slugs whatever throughout Sweden, Finland and Lapland 2, It is 

 curious to note, and not only curious but in view of the question of the 

 distribution of Fasciola hepatica also important to note what follows. 

 In 1875 Dr. Mörch appears, after thus adding Arion hortensis to his 

 former list of Greenland Mollusca, to have been content to leave the 

 entry of »Zma.r agrestis L. according to Wormskiold« untouched; though 

 in smaller type, feeling probably that as the entry of the animal was 

 overtly made only on the authority of Wormskiold, he was in no way 

 pledged either to holding that it was Limax agrestis and not Limax 

 tenellus which existed in Greenland, or indeed to holding that any Limax 

 whatever existed there. What completes my case is the fact, that in 

 1877 when preparing a list of the Greenland Mollusca for the English 

 Translation of Dr. Rink's »Grönland« of 1857, Dr. Mörch omits all 

 mention of Limax agrestis altogether, and his entry runs simply as 

 follows, p. 436: 



Class. 1. Androgynea^ 

 Order 1 . Geophila Fér. 

 1. Arion fuscus^ probably introduced. 

 If we follow Dr. Mörch therefore, we shall strike Limax agrestis 

 out of the list of Greenland Mollusca, and hold ì\\ìàt Arion horte7isis, 



1 Middendorff indeed in his Sibirische Reise, II. 1851. p. 419 omits the 

 name of this small slug from his list of Circumpolar Freshwater and Land Molluscs, 

 but 5 pages further on 1. c. says in a note »Vielleicht ist Limax [Arion] subfuscus 

 Drap. (Drap. Moll. p. 125. PI. IX, 8. Limax fasciata , Nillson , Hist. Moll. Suec. 

 1822. p. 3) eine circumpolare Art dieses Geschlechtes« and he proceeds to note its 

 discovery by himself within the polar circle in Finland feeding on Sphagnum as also 

 in Lapland feeding on Fungi up to 690. ]S^. L. S ehre nek, Reise im Amurland 

 1859 — 1867. II. p. 692, whilst identifying the Limax siibfuscus of Draparnaud with 

 the Arion hortensis ofFérussac, and so with the Limax fuscus of Müller and 

 Lin ne us, confirms the view as to its circumpolar character and uses it as an argu- 

 ment for its being indigenous in America. 



2 Of course the fact of its being a circumpolar and boreal form is not incompa- 

 tible with the suggestion that it may have been introduced by man. Its inconspi- 

 cuousness and its small size make it easy of transport, and like some other northward 

 ranging animals, it has attached itself in great numbers to human horae.steads. 



