62 LAND AND FRESH-WATER SHELLS OF N. A. [PART I. 



of the surface are very fine, and so much compressed as to appear 

 in some lights to be carinated. There is often a well-defined row 

 of spots down the back. The eye-peduncles are long and deli- 

 cate, the mantle sometimes terminates posteriorly in an obtuse 

 point, and the locomotive band of the foot is narrow and well 

 defined. There is a prominent ridge on the head and neck 

 between the eye-peduncles, and a furrow marks the edges of the 

 foot. It is active in its motions, turns rapidly, and often bends 

 the body so as to form two parallel lines. It does not secrete 

 mucus so freely as Limax agrestis. The carina is often yellowish. 

 The testaceous rudiment is oblong-oval, convex above and con- 

 cave below, thin and membranaceous in young individuals, with 

 the superior surface smooth and covered with a delicate perios- 

 tracum, and with the lower surface uneven. No spiral arrange- 

 ment is visible to the eye, and it appears to be only a thin 

 testaceous plate, imbedded in the mantle. In old individuals it 

 attains a greater thickness. 



It inhabits cellars and gardens in moist situations, in the cities. 

 It is considered noxious to vegetation. It feeds upon the leaves 

 of plants in kitchen gardens, and upon the remains of the cooked 

 vegetables, and bread, thrown out from houses. Its most common 

 habitat is in cellars, where it makes its presence most disagreeable 

 by attacking articles of food, and especially by insinuating itself 

 into vessels containing meal and flour. It is common, but not so 

 numerous as Limax agrestis. The young suspend themselves 

 by a thread of mucus. 



This species is of foreign origin, but the period of its introduc- 

 tion is not known. It was noticed by Mr. Say, more than forty 

 years since. It is probable that it inhabits all the cities of the 

 sea-coast, and their vicinage, and some of the cities of the interior. 

 Jaw of a light horn-color, its amterior surface 

 not on one plane, but projecting towards a 

 strong median vertical carina ; arcuate, ends 

 square, striated, concave margin smooth, with 



a well-developed median projec- 



Fig. 104. 

 tion. Fig. 103 represents the 



usual form of the jaw, which agrees with that of a 



foreign individual figured by Moquin-Tandon. 



Fig. 103 was taken from a very large individual 



from Massachusetts. 



