16 LAND AND FRESHWATER 
overhanging lobe, the pedal line very distinct and segmented, termi- 
nating at the upper margin of the mucous gland, the foot with a 
broad pedal margin, segmented (fig. 6). .Mantle—the right shell-lobe 
is moderately large and extends over the region of the body-whorl 
(Plate IV. fig. 2); it extends quite round to the posterior margin 
(figs. 4, 5), and unites with the left shell-lobe, which is very long and 
well developed (fig. 3), and spreads over the edge of the peristome 
from near the respiratory orifice. The right dorsal lobe is triangular 
in shape, and the left dorsal lobe is long and rather narrower than 
the shell-lobe adjacent. The genital organs in one specimen were 
very small and undeveloped, and were not very well developed in 
the second specimen ; they show the presence of a thick bluntly 
cylindrical amatory organ (dart-sac) (fig. 9, D). The penis is much 
convoluted, and is closely folded together, having a cxecum-like pro- 
cess (kalk-sac) (fig. 10, c.c.) midway between the vas deferens and 
the retractor muscle, exactly as in H. bicarinatus, Semper, and H. 
ceratodes, Pfr., from Luzon, but which have no amatory organ. The 
ovo-testis, hermaphrodite duct, &c. were not made out. Helicarion 
cuming? is also somewhat similar, and possesses this organ. 
Odontophore (P1. LY. fig. 12). The buccal mass is large, the radula 
is nearly as broad as long, with a very large number of teeth in each 
row. The ribbon was delicate, and was broken in taking it out; but 
88 rows were counted in one specimen and 97 in the second: we 
may take 100 as the probable number. The dental formula is 
120 (2+7) .1.(7+2) 120, 
ye | Thel05 1h Aellsia). 
The central tooth is broad, large, bluntly pointed, with two small 
basal cusps on either side, on a broad oblong base. The next median 
eight are large, broad, and sharp-pointed, but decreasing in breadth 
outwards ; each has one short basal cusp on the outer margin. Each 
median has a smali notch on the inner margin, its position halfway 
between the apex and the outer cusp. In No. 8 it is still nearer 
and is less developed. In No. 9 it is hardly to be seen; the tooth 
is narrower, while the outer basal cusp has advanced its position 
close up to the point, and No. 10 is changed completely into a long, 
narrow, bicuspid lateral. More than one hundred such teeth suc- 
ceed, all of the same size and shape; then the points become blunter 
(fig. 12 a), with only an indication of the bicuspid form, and finally 
the last have a single, blunt, rather square point (fig. 124), and the 
outermost diminish much in size and are short and pointed. This 
radula is therefore very peculiar, assimilating to that of Macrochlamys 
on one side in the general character of the well-developed median 
teeth, but differing widely in the very great number of the laterals, 
the formula of Macrochlamys being 
40 to 50.12.1.12.40 to 50, 
Of Do els Do. 
The jaw is strong, straight in front, and longitudinally striate, 
thus differing again from Macrochlamys and its allies (Girasia, 
