MUSEUM OF COMPARATIVE ZOOLOGY. 157 
Arionta. (p. 353.) 
The species are not well grouped in the text. The following is more nat- 
ural: — 
Arionta Mormonum Traski. 
' Arionta arrosa. 
tana belongs to the Oregon fauna. 
species. 
Townsendiana. Carpenteri. 
exarata. sequoicola. 
* Diabloensis. 
Californiensis (including reticulata * 
Nickliniana, ramentosa, Bridgesi) Dupetithouarsz. 
* * 
intercisa (including redimta). ruficincta. 
i Gabbi. 
Ayersiana. te 
iD Kelletti. 
tudiculata. Stearnsiana, 
cS 
The geographical distribution of the species is very peculiar. A. Townsend- 
I doubt its ever having been found in 
Tuolumne Co., California. A. Mormonum belongs to the Sierra Nevada 
counties, as does A. tudiculata, which also is found in southern coast coun- 
ties. All the others are restricted to the coast counties, ranging as stated in 
the text, the following being island species: A. ruficincta, Gabbi, intercisa, 
Ayersiana, and Kelletti. A. Stearnsiana and Carpentert are Lower Californian 
The lingual dentition of all the species is essentially the same, excepting 
Townsendiana and ruficincta, which have tricuspid centrals and inner laterals. 
The genitalia are the same in arrosa, exurata, Nicklimana, Californensis, Ayers- 
cana, tudiculata, Traskr, Carpentert, sequoicola, Diabloensis, and Dupetithouarsv. 
From these the genitalia of Mormonum differ very essentially, being more 
nearly allied to that of Aglaca fidelis and infumata. A. Townsendiana has sim- 
ple genitalia, without the accessory organs usually found in Arionta. 4. Kel- 
letti and Stearnsiana have the organs still more complicated with accessories. 
A. ruficincta and Gabbi are related by their genitalia to the last, but differ 
considerably in wanting the accessory duct of genital bladder. 
I have not examined the genitalia of intercisa. 
Arionta arrosa, Goutp. (p. 354.) 
J. G. Cooper, in Proc. Cal. Ac. N. S., 1875, p. 16, indicates a variety, /ol- 
dervana, and another variety, Stiversiana. 
