216 PROCEEDINGS OF THE ACADEMY OF 
A. fidelis (pl. XIII., fig. 8) has 48—-1—48 teeth, with 15 perfect 
laterals. The first marginal is shown in b, an outer marginal in c. 
Usually the first marginals have a side cutting point. 
Hi. infumata (pl. XIII., fig. 9) has 45—1—45 teeth, with 16 late- 
rals. Fig. 6 is the 17th tooth, from a different portion of the 
membrane from c, which is the 20th; they show variation in the 
transition teeth as to the presence of the side cutting point. Ex- 
treme marginals are shown in d. 
Of the dentition of the other species of Aglaja foreign to our 
limits but little is known. H. Ghiesbreghti (see Moll. Mex. et. 
Guat.) has very dissimilar teeth, especially the marginals. H. semi- 
clausa (Malak. Blak. XV., pl. IV., fig. 4) also differs in its denti- 
tion. The jaws of these species agree with those of infumata and 
fidelis. 
Subgenus ARIONTA. 
Jaw thick, high, arched, ends but little attenuated, blunt; cut- 
ting margin without median projection ; anterior surface with a 
few, separated, stout ribs, deeply denticulating 
either margin, and so disposed as to leave 
za each end of the jaw free from ribs. I have 
: H iS counted 6 ribs on the jaw of arrosa; 9 in 
TUN Townsendiana; 6 in tudiculata ; 6 in Nickli- 
Jaw of Helix arrosa. § niqna; 6 in redimita ; 6 in exarata ; 5 in Dia- 
bloensis ; about 7 in Carpenteri ; 3 in ramentosa ; 5 in Californi- 
ensis; 4-6 in sequoicola ; 8 in Traski; 8in facta; 6 in Kellett ; 
9 of unequal size in Stearnsiana. The jaw of ruficincta differs 
in having over 10 ribs covering its whole surface, and in being 
only slightly arcuate. 
i? 
Lingual dentition of Helix facta. 
I have not examined the following species: inéercisa, Mormo- — 
num, Dupetithouarsi, Gabbr. 
The subgenus is almost exclusively confined to our limits. There 
