20 NEW-YORK FAUNA — MOLLUSCA. 
FAMILY LIMACIDA. 
Body elongated, semicylindrical, flattened beneath. A wrinkled mantle on the anterior part 
of the body in most species, sometimes covering the whole superior or entirely wanting 
surface. In this mantle is occasionally found a flat shell, or more frequently a few calca- 
reous grains. Two or four retractile tentacles ; the upper and posterior pair larger, 
oculiferous. When only two tentacles, there is a pair of labial appendices. The pulmo- 
nary cavity variously placed. The position of the vent variable. Terrestrial or marine. 
Oss. The animals of this family are known in popular language under the name of Slugs, 
or Slug-worms. They inhabit moist places, and move by successive contractions of the 
muscular fibres of the foot, leaving a shining trace in their path. Feed on vegetables, and 
are very voracious. They are mischievous in the gardens in some parts of Europe; but 
owing probably to the lesser humidity of our climate, their numbers, and consequently their 
injurious effects are comparatively trifling here. 
The Limaces of the United States have, until recently, been little studied. Mr. Binney is 
the only American naturalist who has investigated the subject to any extent, and his nomen- 
clature will for the most part be adopted in this family. 
GENUS LIMAX. Linneus. Lamarck. 
Animal with its body more or less elongated, semicylindrical, tapering to a point. Mantle 
partial, and placed on the anterior portion of the body, wrinkled. Head tolerably distinct, 
retractile. Four retractile tentacles; the upper pair longest, and bearing the eyes. Foot 
occupying the lower part of the body, without processes, and scarcely distinct from the 
rest of the body. Breathing-hole and vent on the right side of the body. Generative ori- 
fice between or near the upper tentacles. 
LIMAX AGRESTIS. 
PLATEL. FIG.4.—(STATE COLLECTION.) 
LL. agrestis. Linn. Lam. An. sans vert. Ed. 2, Vol. 3, p. 264. 
L. tunicata. Goutp, Invertebrata of Mass. p. 3. 
LL, agrestis. Binney, Desc. Limacide, Bost. Journ. Nat. Hist. Vol. 4. 
Description. Body with numerous minute longitudinal interrupted wrinkles, and a distinct 
ridge extending from between the upper pair of tentacles to the mantle, with a furrow on each 
side. Foot narrow, with two distinct longitudinal furrows on each side. Tail somewhat 
acute. Mantle contains within the rudiment of a delicate oval shell. The mantle is elliptical 
or oblong-oval, much elevated, convex, and, in a state of repose, covers nearly one-half of the 
body ; when in motion, scarcely equals one-third of the length of the body : its surface with 
