ScHARFF — On the Slugs of Ireland. 529 



Agriolimax laevis, Miiller. 



Limax laevis. Miiller, Ilist. Venn., 1774. Limax bruiineus. Draparnaud, 

 Tahle IIoll, 1801. Agriolimax laevis. Lessona and PoUonera, Monogr. Limac. 

 Hal 1882. 



(Plate LVL, fig. 7.) 



Body of a purplish brown colour. Mantle about one-half the length of body. 

 Slime v^atery. Intestine without a ccBcum. 



External Characters. — This slug has not been recorded before from Ireland. It 

 was discovered by Mr. Rathborne in Lord Massy's estate at Killakee, near Dublin, 

 and brought to me for identification. I shortly after found two additional speci- 

 mens in the same place, i.e. along the banks of an old fish pond. Unfortunately 

 none of the specimens were full grown, but I at once distinguished it, as I had 

 expected to find it before, it having a very wide distribution, ranging all over 

 Europe and America. 



The best description which I have seen of this slug is that by Heynemann 

 (14). According to him A. laevis differs chiefly from the closely allied A. agrestis 

 by the size of the mantle, which is almost one-half the total length. The back is 

 only very slightly keeled towards the end of the body, which is of a dark purplish 

 brown colour throughout. Simroth states that younger specimens are of a dark 

 gray, but those I found which only measured 3 mm. and 10 mm. respectively 

 were precisely the same in colour as the largest which measured 15 mm. Its 

 maximum length, according to Heynemann, never exceeds 20 mm. (about three- 

 quarters of an inch), so that it is the smallest of our native slugs. The neck can 

 be stretched out very considerably. The mucus is perfectly clear and transparent, 

 by which the species can perhaps most easily be recognized. 



The shell, especially in younger specimens, is often visible through the mantle, 

 and its outlines are indicated by a golden yellowish colour. 



Anatomy (Plate LVIL, fig. 29). — All the specimens I found being immature, the 

 reproductive organs were not fully developed. The intestine is similar to that in 

 the last species, but the ccecum is entirely wanting. The largest specimen, 

 measuring 15 mm., which I dissected, had only the female reproductive organs 

 developed. This agrees with Simroth's (38) observations, who found that the 

 female portion of the generative organs was generally developed before the male 

 portion. The hermaphrodite gland [hg.) is dark, the rest of the reproductive 

 organ being much the same as in ^. agrestis, with the exception perhaps of the 

 penis, which, according to Simroth is hammer-shaped, the flagellum being of a very 

 different shape from that in A. agrestis (32 Plate ix., fig. 17). 



TKANS. ROY. DUB. SOC, N.S. VOL. IV., PART X. 4 E 



