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Show 2 0 6 MR. R. SHELFORD ON MIMETIC INSECTS AND [N o v . 4, represent very closely the whorls of a spirally coiled snail-shell, such as Helix. The spider occurs in Kuching, and is generally found resting on leaves, sometimes with the cephalothorax turned right under the abdomen, in which position it is readily mistaken for a snail-shell, or with the cephalothorax in the normal position. In the latter case, if disturbed, this part of the body is immediately doubled under the abdomen and the animal usually rolls off the leaf, especially if a small one, and becomes lost in the decaying vegetation carpeting the ground below. I have been unable to discover any web, nor have I seen the manner in which the animal hunts or seizes its prey, but it seems probable that this is an example of one of those doubly significant devices whereby an animal is enabled not only to avoid its foes (in this case predatory wasps) but also to approach its own prey unobserved. [It is possible that this resemblance is cryptic rather than mimetic. The former interpretation seems to be valid in the case of the British larva Aspilcites gilvaria, which also resembles a snail-shell.-E. B. P.] ii. Mimic. Amycicea lineatipes (Pickard-Cambridge). Model. (Ecophylla smciragdina (Fab.). I am indebted to Mr. II. N. Ridley for leave to incorporate in this paper the observations which he has made on this mimetic species, which as yet I have failed to find in Borneo. The ant under notice is an extremely common and ferocious species, chiefly remarkable for its nest-building habits. Mr. Ridley has described these habits in the Journal of the Asiatic Society, Straits Branch, 1890, No. 22, p. 345. The spider is of the same colour as the ant (reddish brown), and bears on the posterior part of the rather acutely pointed abdomen a pair of black eye-like spots, so that it is the abdomen of the spider which corresponds to the head, the cephalothorax to the abdomen of the ant. Both mimic and model are found together near the nest of the latter, and so close is the resemblance between the two that the spider is able to prey with impunity on the ants: I have taken a specimen of a spider with the body of an ant sucked nearly dry in its jaws; and Mr. Ridley has seen an individual pounce on an ant and then dropping from its foot-hold on a leaf, hang suspended by a silk thread in order to complete its meal in safety. No web is spun by the spider, but a round disc of silk, probably the egg-cocoon of this species, was found on the under surface of a leaf much frequented by the spider and its models. iii. Mimic. Scdticas attenuatas (Pickard-Cambridge). Model. An Ant. Mr. Ridley also sent me from Singapore a remarkable little Attid with a well marked constriction about the middle of the |