44 



FRIDTMJOF ØKLANIJ. M.-N. Kl. 



down the sides, sometimes even so far as to produce an animal with 

 quite hlack sides. 



Distribution. As a result of confusion with other species, especially 

 with Arion circnuiscriplus, the range of this species cannot be fixed with 

 desirable certainty. Several times before I have pointed out how authors 

 of tile last century erroneously recorded it as common in large parts of 

 Scandinavia, and, relying on these statements, Taylor in his admirable 

 Monograph has given a quite false map of its distribution. 



The most northern locality of the species is about 63"' N. L., as I 

 have found it in the neighbourhood of Kristiansund ; in the south it occurs 

 in the Pyrenean Peninsula and in Italy. There are a few localities 

 in the eastern parts of central Europe, viz. in western Russia and, more 

 to the south, about as far as to the Danube. Otherwise the species is most 

 common in central Europe and in the British Isles; further it occurs 

 in the Faroes and has been introduced by man into St. Helena, (according 

 to Heynemann 1906), and into North America. 



With regard to Scandinavia the species must preliminarily be struck 

 out in the case of Sweden (Westerlund 1904), but has been recorded 

 from Denmark in some places in Jutland and Seeland (Steenberg). 



In Norway (map 4) it was stated by Tidemand-Ruud to occur at 

 Kragerö, as was briefly mentioned under "Historical Systematics". I have 

 since collected it at Teien and V. Aker (Kristiania), and at Kristiansund, 

 Molde, Aalesund and F'lorö. The scattered localities in Scandinavia give 

 the impression that the species has been introduced by man, a possibility 

 which is strengthened by its habits of life. 



Bionomics. The specific name (liortensis — garden) is quite charac- 

 teristic, this form being especially found in gardens, parks etc. In such 

 localities it occurs in great numbers, and, therefore, may easily be trans- 

 ported to other places with decorative or utility plants. Owing to its 

 great numbers it is said to be rather injurious to gardens ; according 

 to Taylor it devours many kinds of vegetables, from decaying vegetation 

 to roots and stems. 



As regards congress the same author quotes the observations of 

 E. J. Lowe, to the effect that this only occupies little more than half a 

 minute. The animals are mature at an age of 4 — 7 months, according to 

 KüNKEL, whose examinations may be summed up as to reproduction and 

 development. The laying extends over a period of about 2 — 3 months, 

 and in 5 — 8 hatches, each containing 12—80 eggs, 158 — 203 eggs are 

 deposited. These are whitish and transparent, but later on grow yellow and 

 opaque; the shape is always oval, with a length of 2,5 — 3,5 mill., and a 

 breadth of 2 — 2,5 mill. 



According to the temperature the young are hatched after a period 

 of three weeks or more, being of a bluish white colour; from the descrip- 

 tion it seems as if the lateral bands are absent. During growth, how- 



