202 SUPPLEMENT 
The asiphonobranchia appear in general to be less car- 
nivorous; perhaps they are not so at all, or take indifferently 
animal or vegetable nourishment, in a state of putrefaction. 
They seem, in fact, to make use of their proboscidiform un- 
armed muzzle rather to swallow rotten vegetable matter, than 
to masticate it. This is certain, at least, in the terrestrial 
cyclostomata. 
The pulmobranchia, on the contrary, are most generally 
phytophagous, and they chew or cut the substance of which 
they make their nutriment in small pieces, which they swallow 
by little and little. We have already seen that their mouth is 
armed always with an upper cutting tooth, and denticulated 
on the opposite side of the lingual mass. It is said, however, 
that the testacella swallows earth-worms whole, drawing them 
by little and little into the intestinal canal. 
The chismobranchia, the monopleurobranchia, are probably 
in the same situation as the asiphonobranchia, since they have 
no teeth to the mouth. 
The pteropods also appear not likely to chew their prey, 
but to suck it, or take it in a state of decomposition, for the 
same reason. 
We may say as much of the cyclobranchia, inferobranchia, 
and even of the polybranchia, although in this last order there 
are some genera, such as those of tritonia and scyllea, in 
which there are two jaws acting laterally, like the blades of 
scissors, and which consequently ought at least to cut their 
nutriment. 
As to the nucleobranchia, it appears that they feed on small 
animals. The cervicobranchia are perhaps in the same way, 
but it is more probable that their aliment is composed of sub- 
stances in decomposition. 
In the entire class of the acephalophora, this must be still 
more necessary, since the mouth of these animals, soft in all its 
parts, could not exercise the least action on bodies of the 
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