246 ARIOLIMAX. 



G. NUMIDICUS, Bourg. PI. 58, figs. 45, 4?. 



Nearly smooth, the rugae barely perceptible; shield and back 

 more or less blackish, sides yellowish with a black band ; foot 

 obscure, yellowish, with a more obscure median zone ; mantle 

 oblong, rounded at either extremity, minutely granular. 



Length, 60 mill. 



Northern Africa, Gibraltar. 



Genus ARIOLIMAX, Morch, 1860. 

 A. COLUMBIANUS, Gould. PL 59, figs. 51, 52. 



Dark, dirty greenish yellow, sometimes clouded with large 

 purplish black irregular blotches ; body large and corpulent, 

 anterior portion elevated, back rounded, posteriorly strongly 

 carinated, with a caudal mucous pore ; foot-margin ruffled, with 

 transversely pblique markings ; surface longitudinally coarsely 

 rugose. Length, 6 inches. 



Shell-plate oblong, large. 



Pacific Region of the United States. 



Abounds in dense damp forests near the coast. It is 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 trees, 

 etc. Dr. Cooper remarks that when alive it is smooth, not rugose 

 as described and figured. Prof. Wetherby has named, but not 

 described a var. Hecoxi. 



A. CALIFORNICUS, Cooper PI. 59, figs. 53, 54. 



Resembling A. Columbianus in form or color, but with the 

 dorsal grooves much more numerous (26-36), often twice as 

 many, and the connecting reticulations transverse. The dorsal 

 grooves are colored like the rugae, but the grooves of the upper 

 margin of the foot are colored brown, sometimes very pale, and 

 the stripes wider at every fourth or fifth, like the grooves; longi- 

 tudinal division of the sole very faintly perceptible. Shell-plate 

 differing in form from A. Columbianus. 



Near San Francisco, and in the Sierra Nevada, Gal. 



The external difference from A. Columbianus is very slight ; 

 but the shell-plate and the genitalia give distinctive characters ; 



