54 ikiirnijoF øKLANij. M.-X. Kl. 



ing-|y, the s n h - j^^f n ii s Ariiiin iiliis, ti.iscfJ ii|)oti llu; anterior position oi orifi- 

 ciiiiu i^niiidlr and to uliicli Aiion iiilrnitct/iiis has been counted as belonging, 

 must l)e rejected, the saidcharacter not even being constant in the same 

 species (p. 46 — 47). This conclusion is supported by the fact, that at any 

 rate in the Norwegian stock of Arion circiunscriphis, i. e. in a typical Avion, 

 the genital orilice has an advanced position (p. 36; fig. 1 1. 



The Norwegian stock of Avion iiilcvnicdiiis has a powerful genital 

 retractor and the epiphallus with a marked transition from the vas 

 deferens (fig. 46). The jaw is of the common generic type, in contrast to 

 what is stated in regard to foreign specimens (p. 48, fig. 42 — 43). 



The species is new to Norwegian fauna, being found on the west 

 coast between Kristiansund and Farsund (map. 5). 



