Rev. B. J. Clarke on Irish species of the genus Limax. 335 



meets in a point at the extremity of the tail, which is sensibly- 

 keeled. This light dorsal band is bounded on either side by a 

 dark gray colom-ed fascia, often irregular and interrupted, be- 

 neath which the sides are variously mottled or marbled with dark 

 gray, marked more or less with little pale oval spots, which some- 

 times separate off another but very irregular fascia. This latter 

 character is not however often apparent. The lower part of the 

 sides pale whitish or yellowish. 



The mantle is rounded anteriorly, and tapers off to a blunt 

 point posteriorly; it is finely and concentrically striated, and 

 marked on either side with a narrow dark-coloured fascia, which 

 is broadest, and usually darkest, immediately over the pulmonary- 

 orifice, and narrows off towards the head ; each fascia is again 

 narrowly margined with pale yellowish or whitish, the intervening 

 spaces on the back and sides irregularly mottled and marbled 

 with the same dark colour as the fasciae. The pulmonary orifice 

 is situated toward the hinder extremity of the mantle, small, 

 round, and arched over by the dark lateral fascia, which passes in 

 a circular form above it. 



The head and tentacles are grayish with a slight vinous tinge ; 

 on each side of the former the blue retractile nerve is seen through 

 the translucent medium of the neck. The upper tentacles are long 

 in proportion to the lower ones. The sole of the foot is whitish, 

 the central band somewhat narrower than the side ones, and re- 

 markably translucent. 



The internal shell (PI. X. fig. h.) is of an oval form, thin and 

 slightly concave, marked with circular lines as in Limacella parma. 

 When just removed from the animal they are translucent, of a 

 membranaceous consistency, but on exposure to the air bepome of 

 a more opake white with a silvery lustre above. The marginal 

 membrane is well-defined, and being broadest towards the interior 

 portion, gives to that part of the shell an appearance of greater 

 width, and is narrowed off towards the apophysis of adhesion. 



The young (PI. XI. figs. 9, 10.) are vinous- coloured ; the 

 fasciae in general are more decidedly marked and better defined 

 than in the adults. 



This Limax is subject to much variety in the markings, both 

 as to quantity and intensity, but scarcely ever varies in colour ; 

 sometimes the light dorsal band is obliterated and the body is of 

 a uniform blue-gray colour, sparingly and irregularly marked 

 with streaks of a darker gray. Not unfrequently the animal is of 

 a uniform glaucous colour without any markings, the situation of 

 the light dorsal band being marked out by a few scattered, oval, 

 whitish spots. 



I shall now point out a few of the diagnostic characters by 

 which it is distinguishable from all other British species of Li- 



