280 



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



Liiaax columbtanus, Gould, in Terr. Moll. II, 43, pi. Ixvi, f. 1 (1851) ; U. S. 



Expl. Exped. Moll. 3, f. 1, a, b (1852). 

 Ariolimax colutnbianus, Morch, Mai. Blatt. VI, 110. — W. G. Binxey, Am. 



Journ. Conch. I, 48, pi. vi, f. 11-13. 



Fi?. 500. 



Internal shell longer than broad, hexagonal, ends pointed. 



Jaw narrow, arcuate, dark horn or red- 

 dish ; anterior surface with more than 

 fifteen coarse, crowded ribs, denticulatiug 

 the concave margin. 



Lingual membrane very broad, teeth 

 57 — 1 — 57 ; centrals tricuspid ; laterals 



Jaw of 

 Ariolimax columbtanus. 



and uucini bicuspid. 



Fig. 501. 



Lingual membrane of Ariolimax columbianus. 



Specimens referred to this species liave been found in Washing- 

 ton Territory, Oregon, and California (Strs. of Fuca to Santa 

 Barbara, Cooper). 



In form, marking, and coloring it may be compared to Arion 

 empiTicorum of Europe. 



Dr. Cooper remarks : — 



" Thi^ large slug abounds in the dense damp forests near the 

 Pacific coast, and was not observed by me in the dry region 

 east of the Cascade Mountains. It is to be found every month 

 of the year in Washington Territory, being even more abundant 

 in the rainy winter than in warmer seasons ; its activity being 

 checked only by extreme cold, while it cannot bear continued 

 drought. It not unfrequently drops from the trees, &c. This 

 slug grows to the length of six inches, but shrinks to a third 

 of that size in alcohol. Its surface is smooth, not rugose, when 

 alive, as represented in Dr. Binney's plate, and its color is a pale 

 yellowish-olive, usually more or less blotched with black." (Pae. 

 R. R Rep. p. 377.) 



