January 18th. 1897, .] Proceedings. xxv. 



Mr. Rogers exhibited a specimen of a curious caterpillar 

 from Rio de Janeiro, and read the following letter from Mr. 

 Bower : — 



11 In walking through one of the beautiful hillside woods 

 " [of Rio de Janeiro] the other day, I saw what I took to be 

 " a patch of a dark-coloured moss, growing on the trunk 

 "of a tree. This patch was approximately circular, and 

 " about 6 in. in diameter. Near it, at a distance of about 

 " 4 in., was a smaller patch, about 2 in. in diameter, of the 

 11 same nature. The moss, as it appeared to be, was in 

 " fruit, as I thought. I reached forward to get a little of 

 " it, but upon touching it, I observed a curious quiverin 

 " motion which caused me to withdraw my hand. On 

 " touching it again I noticed the same thing, and only after 

 " the most careful examination at the best visual distance 

 " of about ioin. I saw that what I thought to be patches 

 11 of moss were congregations of caterpillars, closely and 

 " densely crowded together. Even after I had assured 

 " myself of the fact, I remained quite astonished at the 

 " resemblance. 



" The neighbouring trees were clothed with moss and 

 " hepatics of various kinds, and I have no doubt that this 

 " was a striking case of protective mimicry. As you will 

 " see by the few specimens I enclose, these creatures are 

 " covered with hairs, more or less resembling the leaves 'of a 

 " moss, and have besides a number of longer hairs tipped 

 " with tufts which, in life, looked exactly like the spore case 

 " and peristome of a moss. These stalks were erect and 

 " crowded together, and even when examined obliquely or 

 " sideways preserved their extraordinary resemblance. It is 

 " difficult to realise, from isolated specimens, how close and 

 " successful was the mimicry of a patch of dark-coloured 

 " moss, and good enough to deceive the very elect." 



Mr. Stirrup exhibited a number of diagrams of fossil 

 insects found in the coal measures of France, which prove 

 the extreme antiquity of the Insecta. 



