GASTHROPODS 333 
EYES 
In Fulgur the eyes are situated near the bases and upon the 
outer sides of the tentacles; in Buccinum they are extremely small 
and are mounted about midway between the bases and the tips of 
the tentacles. This is the usual position for the eyes in the 
marine Gasteropoda. Only in the pulmonates, or land-snails, are 
the eyes placed at the summit of the tentacles. Sight does not 
appear to be a very important sense in the gasteropods, although 
the eye in some instances becomes a highly developed organ. A 
number’of forms that have the habit of burrowing deep into the 
sand or mud are quite destitute of visual organs, and certain 
cave-dwelling land-shells have entirely lost the sense of vision. 
MOUTH AND PROBOSCIS 
The mouth will easily be seen in both Fulgur and Buccinum. 
It isa small slit with slightly thickened, fleshy lips, and is placed 
on the lower forward portion of the head. In the case of both 
of these genera the mouth is situated at the end of a proboscis. 
It will be noted that Fulgur has a comparatively long and stout 
proboscis, or snout, which is not retractile. Buccinum has a smaller 
one. It is fairly safe to assume that all gasteropods that possess 
a proboscis are carnivorous. This organ is greatly developed in 
some genera, where it actually exceeds in length the rest of the 
animal. In such instances, no doubt, the creature is enabled to 
reach the interior portions of the shells of its victims and to 
devour every vestige of their flesh, for the mouth is most con- 
veniently placed just at the end of this long, trunk-like organ. 
The genera which have no proboscis are, almost without excep- 
tion, vegetable feeders. 
We must now remove the animal from its shell. It is well to 
boil it first, for this does away with the annoying mucous secre- 
tion that is freely exuded by glands in the foot when the creature 
is roughly handled. Alcoholic specimens are apt to be much 
contracted and hardened, and are therefore less satisfactory as 
subjects for anatomical study. If it is not convenient to boil the 
