1896.] NATURAL SCIENCES OF PHILADELPHIA, 349 



Mr. Button writes of the living animal as follows : " He has a 

 way of occasionally raising up the mantle over the respiratory 

 orifice, as shown in the sketch, which is characteristic. The follow- 

 ing are some measurements of a very large specimen : Length, over 

 all, when extended, 7 inches; width, I in.; height, i in.; length of 

 tentacles, f inch. The color is the same throughout, shield included, 

 being an olive brown." 



Figures 4 and 5 of Plate XII were drawn from sketches of the 

 living animal furnished by Mr. Button. Fig. 3 represents an alco- 

 holic specimen, dorsal view. 



Jaw with 10 to 12 ribs (PI. XIV, fig. 11). Teetli as in Ariolimax 

 Californicus, but the outer laterals and marginals have the cusps 

 shorter, less thorn-like, and there are rather fewer bicuspid outer 

 marginals. 



General characters of the digestive system (PI. XIII, fig. 4) as in 

 Ariolimax Columhianus ; but the ascending gut from posterior loop 

 passes under the stomach (instead of over it) and the descending 

 gut from anterior to posterior loop makes one spiral turn less than 

 in that species. 



Genitalia (PI. XIV, fig. 12) lying in the body-cavity like that of 

 Ariolimax. Penis absent, the epiphallus {epi.) small and short. 

 Vagina very long, strong, with plicate internal walls, and provided 

 with a band of retractor fibers. Spermatheca large, of irregular 

 shape, on a short duct. 



Oakland, California (Fred L. Button !). * 



EXPLANATION OF PLATES. 

 Plate XII. 



Fig. 1. Ariolimax Columhianus stramineus Hemph., lateral view of 

 an alcoholic specimen. 



Fig. 2. Ariolimax Columhianus Gld., lateral view of an alcoholic 

 specimen of form maculatus, from Tacoma, Washington. 



Fig. 3. Aphallarion Buttoni Pils. & Van., dorsal view of an alco- 

 holic specimen of average size. 



Fig. 4, 5. Aphallarion Buttoni Pils. & Van., lateral view and dorsal 

 outline of a large living individual in motion, drawn from 

 sketches by Fred. L. Button. 

 All figures natural size. 



