GASTEROPODA. 125 
the right median side of the collar. The head is separated by a 
fissure from the foot, over, and on each side of which, it projects in a 
broad, depressed, transversely oval lobe; mouth vertical, furnished 
with a surrounding oval, fleshy protuberance, like a lip; tentacles 
very short, obtusely conical; eyes very large and black, at the poste- 
rior base of the tentacles, a little on one side. On the right side 
of the animal is a tongue-shaped lobe, which, in crawling, projects ob- 
liquely backwards over and beyond the foot. Colour pale olive, with 
gray specks scattered over the foot and all visible parts of the body. 
Excrement slender, cylindrical, sometimes half an inch in length. 
Placed in a jar of water, holding only half a pint, ten individuals 
remained in it twenty-five days in a healthy condition, without a 
change of the water. They continued for days together attached to the 
sides of the vessel, towards the bottom ; and then again remained for 
as long a time above water. When below it, a bubble of air was 
always visible at the respiratory orifice, from which smaller bubbles 
would occasionally rise to the top. Two individuals placed in a dry 
box died, one on the fourth, the other on the sixth day. Two others 
placed in the same box with wet moss, lived, one for sixteen, and the 
other for twenty-two days. The animal was very sluggish in its 
motions, and when retracted was fully concealed in the shell. 
[Sweic.] 
It is quite evident, from the above description and from the figure, 
that this animal belongs to the family Limniada, and is the analogue 
of the genus Limnea in the southern hemisphere, and that it has no 
affinity to Auricula, where it has usually been placed. D’Orbigny’s 
name for the genus is the oldest; but as it has been already applied 
more than once in Botany, the name Chilina, subsequently given 
it by Gray, would have been preferable. The specimens were found 
in fresh water, in Patagonia, about six miles up the Rio Negro. I 
cannot make out that it differs from the descriptions and figures of 
specimens said to have come from Chili. 
Figures 144, 144 a, two views of the animal, with the shell. 
ANCYLUS ADUNCUS (Gould). 
Testa exigua, oblique conica, viridula, striis radiantibus et striis 
32 
