AlUUN INTEBMEDIUS. 24.'! 



Reproduction and Development.— Tbe congress of this interesting 

 little species lias never been described, but the eggs bave been observed 

 from August quite up to January ; tbey are oval in shape, and very large 

 for the size of the animal, being two mill, long and one-and-half mill, 

 broad or even of a larger size, gelatinous to the touch, semitransparent and 

 pearly-white in colour, with opaline reflections. They have been observed 

 to be deposited in irregular clusters strongly cemented together ^vith a 

 yellowish mucus, but not exceeding twenty in a cluster. 



The eggs hatch in about three weeks after deposition, the young when 

 hatched may be, according to Dr. Scharff, light red, with violet tentacles, 

 gradually changing however until by the time they have attained eight mill, 

 in length they have become pale grey, a colour due to the viscera showing 

 through the semitransparent skin, the head becomes also of a delicate grey, 

 and no bands are perceptible on body or mantle. 



Mr. Gain, whose studies of the development, food, and habits of the 

 slugs have been so complete and valuable, records that the young are 

 usually dark green or yellow, and that the, change in adult life is to a 

 paler coloration. Some of the green variety, obtained early in April, only 

 increased slightly in bulk during the following six weeks, but changed to 

 a greenish yellow with a perceptible slaty-grey lateral band on each side; 

 early in June they had increased materially in size, lost all trace of green, 

 and were quite yellow, with well-marked lateral band, and dusky mid- 

 dorsal line; they gradually became paler and almost white, except the sole 

 and caudal gland, which were of a deeper colour, while the lateral and 

 dorsal banding became fainter and more diffuse; towards the end of July 

 the animals attained maturity and their final coloration, from which time 

 onwards into January the adults and their egg-clusters have been found, 

 but the animals do not appear to survive much beyond that period. 



Food and Habits. — Arion intermedins is described as naturally 

 purely fungivorous, and in Germany is confined to the mo.ss on pine- 

 covered heathy land. In this country it is found chiefly on the various 

 species of Russula, Agaricus and Clavaria, but in captivity it is not nearly 

 so restricted in its diet, eating lettuce freely, and also readily devouring 

 cabbage, watercress, bread, and even paper. Breviere records that it feeds 

 eagerly upon dead or moribund worms and small animals. 



It is not a garden species, nor does it usually frequent cultivated ground, 

 but seems to prefer living in the open countrj^ hiding beneath animal 

 and other refuse, possibly on account of the fungoid growths thereon, 

 they are also found in grass-fields where fungi abound, or on the margin 

 of woods, concealed beneath dead leaves, close by the small fungi which 

 grow in clusters at the foot of the trunks of old trees, and to which the 

 animal approximates so closely in colour, that it has been likened to a 

 small fungus just peeping above the ground. 



When at rest, the animal assumes the hemispherical shape, which is so 

 characteristic of Arion ater, and in this position the remarkable crested 

 tubercles of the body are most apparent. It is fond of burrowing in the 

 earth, where it lies concealed during dry weather, and is also addicted to a 

 peculiar habit of raising aloft the anterior part of its body and apparently 

 looking around, like a stoat, a habit to which L. arborum is also addicted. 



In captivity, the skin soon becomes uniformly distended, and the 

 rugosities effaced, but if kept in somewhat dry surroundings it very 

 quickly becomes sickly and perishes, shrinking up especially posteriorly, 

 but also showing a very peculiar constriction near the middle of the body. 



