98 A MANUAL OF AMERICAN LAND SHELLS. 



and figure tbem iu Fig. D,/, of Plate V. The gradual change from the 

 first lateral tooth to the last marginal tooth is well shown in Fig. H of 

 Plate V, which re^jresents the teeth of A. Hemphilli. (See also p. 50, 

 Fig. 10.) 



There is no retractor muscle to the buccal mass in A. CalifornicuB 

 and A. Columhianus, but a very stout, broad one to the whole head, 

 attached to the outer integument below the buccal mass, and running 

 along some distance on the floor of the general visceral cavity, to which 

 finally it becomes attached. 



Arioliiiiax Coliinibianus, Gould. 

 Color a dark, dirty, greenish yellow, either uniform or in some varie- 

 FiG. 60. t-i^s clouded with large, purplish-black, irregular blotches. 

 The body is large and corpulent, the anterior portion ele- 

 vated, with the back rounded, and the posterior portion 

 strongly carinated ; at the posterior tip there is a mucus 

 pore. The margin of the foot extends beyond the mantle, 

 ^ , ■ , , , , and forms a ruffle around the animal, with transversely 



Internal plate of 7 »> 



A. cohtmbianus. ^y\y\iqy^Q markings. The surface is tessellated with coarse 

 elongated papillae, arranged longitudinally. The mantle is broad, trun- 

 cated in front, minutely granulated, with the respiratory orifice at the 

 posterior third. Face vertically wrinkled; eye-peduncles rather short, 

 thickened at base, colored like the body, and finely granulated; tentacles 

 long and slender. Length, 5^ inches. (See Fig. 58, on p. 92.) 



lAmax Columbianus, Gould, in Terr. Moll., ii, 43, pi. Ixvi, fig. 1 (1851); U. S. Expl. 



Exped. Moll., 3, fig. 1, a, b (1852).— Tr YON, Am. Journ. Conch., iii, 315 



(1868). 

 Arioliviax Columbianus, MoRCH, Mai. Bliitt., vi, 110. — W. G. Binney, Am. Journ. 



Conch., i, 48, pi. vi, figs. 11-13; L. & Fr.-W. Sh., i, p. 279, fig. 499 (1869); 



Terr. Moll., v, 231. 



Internal shell longer than broad, ends rounded. 



Specimens referred to this species have been found in Washington 

 Territory, Oregon, and California (Straits of de Fuca to Santa Barbara, 

 Cooper). It therefore inhabits the Pacific Eegion. 



In form, marking, and coloring it may be compared to Avion empiri- 

 corum of Euroije. 



Dr. Coojier remarks : 



" This 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 Cas- 

 cade Mountains. It is to be found every month of the year iu Wash- 

 ington Territory, being even more ubuudaut in the rainy winter than 



