MOLLUSCA. Sg 
genus in which the shell is somewhat ear-shaped, and the foot very large 
and thick, nearly hiding the shell, which is sunk into it. The tentacles are 
flat and triangular, but unaccompanied by eyes. Although the animal is 
too large to enter the shell, it is provided with an operculum. Vatica (LN. 
canrena, pl. T5, jig. 88) is carnivorous like the preceding genus, and like 
it, has no siphon. It has a large foot (four or five times the length of the 
shell) bearing an operculum. The head is terminated by a pair of lips from 
which a rostrum can be protruded. 
Orver 11. Pneumonoprancuta. This order includes all the spirivalve 
and naked mollusea, whether inhabiting land or water, in which the branchie, 
without being proper lungs, are adapted for breathing air, so that the species 
which inhabit the water are obliged to come to the surface from time to— 
time to breathe air. They seem all to be phytophagous. The order includes 
eight families. | 
Fam.1. Ampullariide. The genus Ampullaria has a globular shell 
several inches in size, which is generally covered with a green periostraca, 
and is provided with a closely fitting concentric operculum, which is in 
some cases corneous, and in others shelly. With Paludina and Valvata it 
forms one of Lamarck’s families, named Peristomata by Reeve. The North 
American species is figured with the animal in the monograph already 
quoted. The head is proboscidiform, the extremity cleft, leaving a conical 
branch half an inch long on each side, and these are used as palpi. The 
mouth is purse-shaped, the tentacles slender, tapering, and more than an 
inch long, the eyes borne upon a secondary tubercle at the base externally. 
The shell is without a notch, yet there is a siphon an inch long which is 
formed by an extension of the mantle folded into a tube. This is brought 
to the surface of the water and air drawn through it, and often expelled 
from it in bubbles when beneath the surface. Guilding describes a shorter 
siphon upon the right side. The animal lives in the rice swamps of Georgia, 
feeding upon living plants. Living mostly in the intertropical regions of 
both hemispheres, where the waters frequently disappear in the dry season, 
Ampullaria has the power of becoming torpid beneath the mud until the 
return of the wet season. Some specimens sent from Egypt to France 
were thrown into water to clean them, and the next day they were found 
moving about. Deshayes dissected some of these, and found pectinated 
branchize, which would place the genus near Paludina, and he describes a 
large cavity, to which he assigns the function of holding a store of water to 
be supplied to the branchie during the period of torpidity. This may be 
correct ; although a further examination will probably show that this cavity 
is adapted to breathe air, and on this account we place it in the present 
order. Planorbis bicarinatus (and probably its entire family) hybernates 
at the bottom of streams with the air cavity filled. The ability to breathe 
air and water by means of distinct organs is not anomalous, as it appears in 
certain reptiles. The sexes are separate. 
Fam.2. Amphibolide. The genus Amphibola (also named Ampullacera) 
has a sub-spiral corneous operculum, and is formed upon a New Zealand 
shell formerly considered to be an Ampullaria. It was found to breathe air 
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