146 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



sinuating 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. 



lliis species is of foreign origin, but the period of its introduction is not 

 known. It was noticed by Mr. Say more than fifty years since. It is prob- 

 able that it inhabits all the cities of the sea-coast, and their vicinage, and most 

 of the cities of the interior. 



Jaw (Vol. I. PI. I. Fig. VI) of a light horn-color, its anterior 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 

 projection. 



The lingual membrane (PI. I. Fig. G) of one specimen^ examined has 

 about 60 — 1 — 60 teeth, with 16 laterals. The centrals and laterals are of 

 the same type as in L. maximus, the outer marginals are also bifid. On 

 other portions of the same membrane the cutting points are longer and sharper. 

 Fig. c represents an extreme marginal. Both of the figures of this spe- 

 cies, published by me, were drawn from lingual membranes of another 

 species. 



The genital system, as well as full anatomy, is figured by Leidy in Vol. I. 

 PI. I. The testicle (1), composed of a globular mass of aciniform coeca, is not 

 imbedded within one of the lobes of the liver. The penis sac (4) is long, stout, 

 cylindrical, receiving the vas deferens (2) and retractor muscle (5) at its apex. 

 The genital bladder (8) is small, elongated-ovate with pointed apex and short 

 duct. 



Limax agrestis, Linn. 

 Vol. III. PI. LXIV. Fig. 2. 



Color varying from whitish through every shade of cinereous and gray to 

 black, and through various shades of yellowish, or amber-color, to brownish, 

 and sometimes irregularly spotted with small black points or dots ; eye-pedun- 

 cles and tentacles darker than the general surface, sometimes black ; mantle 

 sometimes mottled with a lighter color ; base of foot sallow white ; sheath of 

 eye-peduncles indicated by black lines extending backwards from their base 

 under the edge of the mantle. Body when in motion cylindrical, elongated, 

 terminating acutely, the sides towards its posterior extremity compressed up- 

 wards, so as to form a short carina or keel ; foot very narrow. Mantle oblong- 

 oval, fleshy, convex, and prominent, rounded at both extremities, equalling in 

 length one third of the length of the body, its surface marked by prominent, 

 irregularly waved, concentrical lines and furrows having their centre on the 



1 L. & Fr.-W. Sh. N. A., I. p. 63, Fig. 105, is no doubt L. agrestis. Fig. 6, p. 285, 

 of Ann. Lye. N. H. N. Y., VoL IX., would more correctly represent the dentition of this 

 specie? J if the extreme marginals were bifid. 



