FAMILY LIMACID.*: — ARION. 23 



GENUS ARION. Ferussac. 



With the characters of the preceding, but the breathing-hole more in front. Mantle with 

 small granulations, and containing small calcareous concretions. A terminal mucous pore. 



Obs. It is very doubtful whether this should be considered as more than a sub-genus of 

 Umax. 



Arion hortensis. 



Limax hortensis. Lamarck, An. sans yert. ed. Brux. Vol. 3, p. 265. 

 Avian id. Ferussac, Mollusques, p. 65, pi. 2, fig. 6, 

 A. id. Binney, Limacidffi, p. 10. 



Description. Body narrow, expanding somewhat behind, and ending in a truncated point. 

 Surface above with crowded fine oblong tuberosities ; and the flanks with elongated tubercu- 

 lated plates, with furrows between. Mantle small, oval, flattened, its anterior edge nearly 

 reaching the head. It is about one-fourth of the length of the body. A tubercular ridge, 

 with furrows on each side, between the upper tentacles ; lower tentacles very short. Foot 

 separated from the margin of the body by a furrow, and projecting beyond the body behind 

 in a flat and rounded form. The mucous pore is a triangular sinus. Breathing-hole very 

 small, near the edge of the mantle, about one-third of its length distant from its anterior ex- 

 tremity. 



Color. Above whitish or ashen, with occasionally a tinge of brown. On each side of the 

 body an obscure brownish line, uniting over the posterior extremity. Upper tentacles darker 

 than the general surface. Foot whitish. 



Length, 1 ' and more. 



I have followed Mr. Binney in the nomenclature of this species, who appears to consider 

 it as identical with the hortensis of Europe, from its black longitudinal bands. Its hitherto 

 restricted locality (vicinity of Boston), and small numbers, seems to induce that distinguished 

 naturalist to consider it as an introduced species. 



GENUS TEBENNOPHORUS. Binney. 



Mantle covering the whole superior surface of the body. Pulmonary cavity anterior ; orifice 

 on the right side, towards the head. Vent contiguous to, and a little above and in advance 

 of the pulmonary orifice. Organs of generation united ; orifice behind and below the 

 superior tentacle of the right side. No testaceous rudiment, terminal mucous pore, or 

 locomotive band of the foot. 



Obs. This genus appears to be allied to the Onchidium of Buchanan, but I have had no 

 opportunity to examine the species upon which it is founded. In both, the mantle covers the 



