ir>4 HILAX SiJWEEBII. 



The MANDIBLE or jaw is of arcuate form and deep 

 amber colour, anil the chitinous continuation which 

 extends over the upper surface of the mouth cavity is in 

 this species well marUed and distinctly striated ; the line 

 of bedding within the tissues of the head is marked with p,(. 176. — Mandible or 



a dark line; the median beak or rostrum is distinct, jaw of M. styiuerUi, x 12. 

 prominent, and somewhat pointed. 



The LINGUAL MEMBRANE has the teeth not so compactly arranged as in Milax 

 gagates, and the individual teeth are broader, though displaying the same distinctly 

 tricuspid median and inner lateral teeth ; the endoeone, however, becomes gradually 

 lost as the margins are approached, and the marginals are simply aculeate, though 

 some show a distinct tendency to ectoconio bifurcation. 



Fig. 177. — Representative denticles from a transverse row of the lingual teeth of M. sviuerhii, X 180. 

 The animal collected at Dundrum, Ireland, by Dr. ScharfF, and the palate prepared by Mr- W. Moss. 



The formula of a Dundrum specimen, collected by Dr. Scharff, was 

 f-'k+ V +^+ V +f-^ X 105 = 8,715. 



Reproduction and Development. — The conjugation of M. sowerhii, 

 tliough probably occurring throughout the year, is 

 more frequently observed during the colder months. 

 The operation, as in M. gitgates, is very prolonged, 

 usually occupying three to four hours, and Mr. 

 Kew observed one instance in which the union 

 extended over the space of seventeen hours. The 



act is consummated by the mutual transference Feg. its.— Spermatheca of 

 of the elaborate spermatophores, the smooth, nS^n T apS, '*'e''"f ?he 

 attenuated end of which enters the spermatheca presence of the spermatophore 

 first,^ and fills and deflects the narrowed prolonga- ^'^^'^ ^ 



tion of that organ, sometimes so abruptly as to rupture its moorings to 

 the oviduct ; occasionally a second pairing may take place at so short an 

 interval that a second spermatophore may become lodged in the sperma- 

 theca before the disintegration of the first has taken place.'^ 



The eggs, which are comparatively large, l)eing about iive mill, in their 

 longest diameter, are deposited in clusters of a dozen or more in the soil; 

 they are oval in shape, soft and elastic, of a goldeu-brown colour, and 

 possessing a coriaceous white freckled though translucent envelope, which 

 when placed in spirit changes to an opaque white. The progress of their 

 development and the later history has not boon observed. 



Food and Habits. — 3Iiht.r souvrbii is subterranean and gregarious in 

 habit, being often found during the day huddled together in worm-holes 

 several inches below the surface ; it also hides at the roots of plants, 

 amongst dccaynig vegetation, in crevices of old walls, under stones, etc., 

 coming forth during wet weather or at night-fall and retiring at daybreak 

 to the subterranean retreats, into which hits of stalks are frequently dragged 

 to feed on at leisure. It is usually not of common occurrence in the open 

 country, but is in places one of the most abundant garden slugs, pre- 

 ferring soil of a stiff clayey character, owing to its better retention of 

 moisture and the greater prevalence of worm-burrows therein. It is very 



1 Monog. i., p. 376, (f. 700, 701, 2 Monog. i., p. 374, f. 091. 



