15S JOURNAL OF pONCHOLOGY. 



THE LIFE-HISTORY OF ARION ATER AND ITS 

 POWER OF SELF-FERTILISATION. 



By F. W. WOTTON. 



(Read before the Conchological Society, Nov. 4, 1892). 



The study of slug life does not appear to have been very 

 enthusiastically entered upon by British malacologists, and the 

 text-books and other works on the subject written by our own 

 countrymen generally contain statements that have been copied 

 from continental writers as well as from the older English 

 authors without any attempt having been made to verify or dis- 

 prove them. Thus many inaccuracies have been perpetuated. 



This, I feel, is a reproach to us as a Conchological Society, 

 and in laying the present life-history before the members, it is 

 with the earnest hope that others may be induced to take up 

 the work, and carry it on until the whole of the British slugs 

 have been dealt with in detail. 



The facts I am about to adduce are solely the result of my 

 own observations, and I may here state that during the whole 

 time I was engaged working out the life-history of this lowly 

 creature, I watched it at intervals each day and part of each 

 night with but few intermissions. 



Avion ater is one of the largest British slugs. It averages 

 in length when fully extended from 3|- to 7 inches from the tip 

 of the tail to the ends of the tentacles. Fine specimens are 

 occasionally met with which exceed even the latter length — 

 one of the slugs I experimented with totalling 7! and another 

 8 inches. Although this species has been named atei\ they are 

 not by any means all black, as the name implies, but are to be 

 met with in various shades of orange, brown, yellow, and cinere- 

 ous, sometimes mottled or streaked and often unicoloured. 

 This peculiarity has given rise to a perplexing number of varietal 

 names, and I would here ask, in all sincerity, if the time occu- 

 pied by those who seem to make a speciality of seeking out 



J.C, vii., J.-in. iSgq. 



