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Show 1 9 0 2 . ] SPIDERS FROM BORXEO AND SINGAPORE. mimics which came under my observation-namely, a sphingid larva mimicking a snake, a noctuid larva mimicking an ant, a moth mimicking a plant-bug-deserve, however, further notice and are here described at length. i. Mimic. Larva of Choerocampa mydon (Walk.). Model. A Snake, e. g. Dendrophis picta (6 m.). I must confess that I have always hitherto regarded as somewhat fanciful those recorded cases of lepidopterous larvae mimicking snakes and other vertebrate animals, though experiments have shown that the resemblances, even when imperfect, serve to rouse respectful curiosity, if not actual terror, in prospective enemies. I was therefore singularly delighted to secure a larva whose resemblance to a snake was so startlingly accurate that I was for a moment completely deceived. The general colour was a dark olive-brown, becoming lighter anteriorly: the head, the first and second and the dorsal surface of the third and fourth segments were pinkish; at the junction of the third and fourth segments on each side was an ocellus, not a huge black disc, out of all proportion to the mimicked head, as in all the recorded similar examples, but of very nearly the exact size of the eye in such a snake as Dendrophis picta : the lower border of this was margined with bright gold (the colour of the iris in many snakes), giving an upward look and a most malevolent cast to the countenance; the black of the ocellus was so intense and glossy that an idea of depth was given, and it was difficult to believe that one was not looking through a cornea into a pupil. Running through the ocellus on each side was a broad black stripe exactly as in Dendrophis picta, while a wrinkled fold on each side of the lower half of the second, third, and fourth segments gave an admirable impression of the division between the upper and lower jaws of a snake. Not the least remarkable of these extraordinary devices was the flatness of the area bounded by the two " eye-stripes " on the dorsal surface of the third and fourth segments; this area together with the first and second segments were pink, reticulated with fine brown lines and strokes, giving an impression of the scutes on a snake's head; they were particularly well-marked on the first and second segments, being there more distant and distinct, and looking extremely like the divisions between internasal and proefrontal shields. When the larva was moving about with the anterior segments well expanded, the resemblance to a snake was not so startling, but directly it was touched the terrifying attitude was assumed, the anterior segments being drawn in and the front of the body turned towards the aggressor; when, at the same time, the posterior part of the body was hidden by leaves the deception became complete, and if effective enough to deceive, even temporarily, a human being, it must surely be equally effective in deterring less highly organized and more timid foes. |