PACIFIC COAST SPECIES. 101 



down to the tail, as in Columhianus and Californicus, but rather erect, 



giving the appearance of being cleft, and showing much J^'f • ^■ 



more plainly the caudal gland. Mantle quite small, bluntly 



rounded before and behind. Color leaden below, blackish 



above. Length, contracted in spirits, about 30'""\ Dr. 



Cooper gives 2^ inches as the length of the living animal. ^^A.nFJer! 



Atiolimax niger, J. G. Cooper, Proc. Phila. Acad. Nat. Sci., 1872, 147, pi. iii, fig. B, 

 1-4,— W. G. BiNNEY, T. M., V, 234. 



Found in the California Kegion. I have received specimens from 

 Oakland, Bolinas, Santa Eosa, Healdsburg, Sonoma County. They 

 all agree in their genitalia, as well as in outward form. 



This species, preserved in alcohol, is most readily distinguished by its 

 smaller size, dark color, subcylindrical body, and especially by its 

 bluntly truncated posterior termination, which is decidedly cleft at the 

 mucus pore. The nature of the pore is described above (p. 96). 



Jaw, see p. 93. 



Ariolimax niger, also (Plate Y, Fig. D, Terr. Moll., V) has the 

 same type of dentition as A. Columhianus ; the side cusps of the cen- 

 trals are, however, more developed. On one specimen I found mar- 

 ginal teeth with one inner stout, short, rounded cutting point, and 

 two shorter, rounded, side cutting points (see Fig. F), instead of the 

 usual long cutting point. This is the only variation in the dentition of 

 the genus which I have noticed. There are about 48-1-48 teeth. 



On opening the body of A. niger (Terr. Moll., V, Plate XII, Fig. F) 

 the genitalia are found in the usual place, the testicle lying quite at 

 the rear of the visceral cavity, near the extreme point of the upper 

 lobes of the liver, hardly imbedded in it, connected with the ovary by 

 a long epididymis. The testicle is globular in form, composed of black, 

 aciniform cseca. It contrasts in color wiih the dirty white of the liver. 

 Color, however, I have not found constant in the internal organs of 

 laud shells preserved in spirits. The above-described arrangement o'f 

 the testicle is as usual in Liniax, Arion, and other slugs. It forms an 

 excellent specific character for A. niger, the position of the testicle 

 being quite different in A. CaUfornicns and A. Colnmhianus, as will be 

 seen above. The epididymis is long, convoluted at the end nearer the 

 ovary. The accessory gland is small. The ovary is large, yellowish. 

 The oviduct and prostate show no unusual characters. The genital 

 bladder is large, oval, with a short duct. The iienis is in a short, 



