ScHARFF — On the Slugs of Ireland. 519 



persists. Thus we usually find that the mantle is uniformly spotted in the adult, except 

 the part between the respiratory orifice and the posterior margin, where we meet 

 with an elongated black mark, the remnant of the lateral band of the mantle. (This 

 is well shown in Reeves' (3-i) figure of L. mazimus.) The general body-colour is 

 usually of a faint reddish-gray, turning into pure gray in spirit, whilst the dark 

 spots and bands often become blue. The tentacles are of a light reddish-violet 

 tint. The mucus, on the nature and colour of which rather too much importance 

 has been placed by previous observers, is whitish, and not nearly so abundant as 

 in L. flavus, and L. marginatus. 



Anatomy (Plate LVIL, fig. 25).— Both Nunneley (31) and Simroth (38) have 

 given such detailed descriptions of the anatomy, that I need only refer again to 

 the most salient features. 



Of the six convolutions of the intestine, four are imbedded in the liver, and 

 two hang freely in the body cavity. The hermaphrodite gland {hg.) is elongated 

 and large, and is connected with the ovisperm-duct (os.) by means of the 

 hermaphrodite duct (M) which takes its course through a portion of the albumin- 

 iparous gland {ag.). The ovisperm-duct is thick and well convoluted, and 

 separates fm-ther down into a vas-deferens or sperm-duct {sp.) and an oviduct 

 {ov.). The former opens into the upper end of a very long penis {jy.), to which a 

 strong retractor muscle (n«.) is attached. The lower portion of the penis unites 

 with that of the oviduct at the genital orifice, so that there is no vestibule. The 

 receptaculum seminis {rec.) opens into the lower end of the penis near the junction 

 of the two ducts. Nunneley (31) gives a good figure and description of the repro- 

 ductive organs, and although he mistook the albuminiparous gland for the testis, 

 this is a comparatively unimportant matter. 



Of course, as in all parts of the body, there are variations in the reproductive 

 organs, and it is a matter of opinion whether, in conjunction with external 

 differences in colour, these should be regarded as sufficient to sub-divide the 

 species. Lessona and Pollonera (28), who have published an elaborate monograph 

 on the Italian slugs, are evidently of that opinion, and a good deal may be said in 

 favour of it. 



I consider the shell of so little importance as a distinguishing feature that it 

 will be enough to say that it is much larger than in any of the other species. 



Reproduction. — The eggs, as far as my observation goes, are deposited in 

 August and September, but I think another deposition takes place earlier in the 

 year. They are very transparent, elastic and slightly yellowish in colour. Their 

 length is 6 mm., and width 4 mm. About a month after their deposition the 

 young appear, and from the first show two distinct lateral bands on the body, 

 reaching to the posterior third of the mantle. The body-colour at this stage is of 



