ARION. 451 



Arion fuscus. 



Color whitish or hg'ht ashy, sometiuics with a tinge of brown, or dark grayish; 

 body cylindrical, narrow, expanding a little towards its extremity, ending in a 

 flat antl rounded termination; head darker than the body, projecting very little 

 beyond the mantle; mantle small, oval, narrow; disk of the foot whitish. A 

 triangular mueus-pore on the upper surface of the posterior extremity. 



Liiiiax fiisrus, MtJLLER, Hist. Venn. ii. 11 (1774). 



Arion hoiiensis, Ferussac, Illst. 05, pi. 2, ligs. 4, 6; Suppl. pi. 96 a (1819). — Binney, 

 Eost. Joiu-n. N. H. iv. 170 (1842) ; Terr. MoU. ii. 27, pi. 64, fig. I ; pi. 65, fig. 2 

 (1851).— Leidy, Terr. Moll. U. S. 249, pi. 2, figs. 1-4, aiiat. (1851).— Dii Kay, 

 N. Y. Moll. 2.3 (1843). — RicEVK, Brit. L. and Fr. W. Moll. 11, figs. 



Arion fitscus, Moquix-Tandox (which sec for further furcigu synonymes). 



Color wliitish or liij,-lit ashy, sometimes with a tinge of brown, or 

 dark grayish ; an obscure, ill-detined, dark colored line or band 

 rises where the mantle 

 meets the bases of the 

 tentacles on both sides, 

 and, extending along 

 the whole length of the 

 mantle to its posterior 

 extremity, converges 

 towards the line of the opposite side ; another band, proceeding from 

 under the posterior edge of the mantle, not qnite continuous with 

 the above described line, runs along the sides of the body to its ex- 

 tremity. Body cylindrical, narrow, when extended very much elon- 

 gated ; expanding a little towards its extremity, and ending in a 

 flat and rounded termination ; its up})er surface is covered with nar- 

 row, oblong, prominent glands, appearing sometimes as if carinated, 

 and arranged in parallel rows, the flanks w'itli elongated tul)crcn- 

 lateil plates and finer granulations. Head darker than the body, 

 projecting very little beyond the mantle. Eye-peduncles blackish, 

 one eighth the length of the body, stout, 1)ulbs translucent, ocular 

 spot at the suj)crior ])art, l)lack. Tentacles immediately under tlie 

 eye-peduncles, very short, conical. Mantle small, oval, narrow, 

 commencing just behind the insertion of the eye-peduncles, less 

 than one third of the length of the animal ; covered w^ith granula- 

 tions tending to a vermiform sha]ie. Disk of the foot whitisli, with- 

 out a separate locomotive band, the marginal boundary between it 

 and the body marked by a furrow, projecting lieyond the body pos- 

 teriorly. Respiratory foramen small, with a cleft to the margin of 

 the mantle. Between the eye-peduncles is a tubercular ridge with 



