The Cambridge natural history . frequently happens that several senses are centred ina single organ, thus the upper tentacles of snails not onlycarry the eyes and serve to a certain extent as tactile organs,but they also carry the organs of smell. The edges of the mantle, which are sometimes specialisedinto lobes, appear to be keenly sensitive to touch in allGasteropoda. In Cypraea (Fig. 81) these lobes, or tentaculae, are aprominent feature of the animal, and also in certain genera ofthe Trochidae (Fig. 82). In most of the carnivorous landPulmonata— Testacella, Ehytida, Ennea—there are de
The Cambridge natural history . frequently happens that several senses are centred ina single organ, thus the upper tentacles of snails not onlycarry the eyes and serve to a certain extent as tactile organs,but they also carry the organs of smell. The edges of the mantle, which are sometimes specialisedinto lobes, appear to be keenly sensitive to touch in allGasteropoda. In Cypraea (Fig. 81) these lobes, or tentaculae, are aprominent feature of the animal, and also in certain genera ofthe Trochidae (Fig. 82). In most of the carnivorous landPulmonata— Testacella, Ehytida, Ennea—there are developed,under the lower pair of tentacles, and close to the mouth, largelabial palps or feelers. These are connected with the cerebralganglion by a very large nerve, and may therefore be supposedto be of extreme sensitiveness. In some of the large carnivorous VOL. Ill N . ORGANS OF TOUCH forms {Glandina, Aerope, compare Fig. 21, p. 54) these palpae are ofgreat size, and curl upwards like an enormous pair of Fig. 9)\. — Cijpraea moneta L., showing tentaculae atedge of mantle, which partly envelopes the shell:Si, siphon ; M, M, mantle ; F, foot ; T, tenta-culae at edge of mantle. (After Quoy and Gai-mard). x f. Fia. 82.—Monodonta canali-fera Lara., New Ireland,showing mantle lobes.(After Quoy and Gai-mard.)
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
