British Orihaiidm. By A. D. Michael. 37 



legs, so that not a trace of those parts can be seen from above, and 

 the whole creature looks not unlike one of the fish-scale flowers 

 which the natives of Brazil make so skilfully. The nymph is very 

 inactive, usually remaining quite stationary in one place, and it 

 must be difficult for any predatory creature to detect it. The 

 mature form is as different from the nymph as can well be 

 imagined ; it is nearly black, and pohshed, does not carry any of 

 its cast skins, hardly has a hair about it, and the few it possesses 

 are quite fine. 



In the latter part of this paper I have described the various 

 nymphs, fifteen in number, which I have traced through to the 

 perfect creature during the present season ; the descriptions are 

 all carefully taken from living specimens, and the same remark 

 applies to the drawings of the nymphal and adult forms which will 

 be found in the plates ; these plates really should have been 

 coloured in order to have done justice to the nymphs ; in the adults 

 it is not important, but in the nymphs colour varies much, and is 

 characteristic. 



Finally, I may say that, in every instance, I have traced the 

 creature by actually breeding it from the nymphal stage, in con- 

 finement, in a glass cell not containing any other creature whatever, 

 and in nearly every instance I have actually seen the perfect form 

 emerge from the nymphal skin. I have, in several cases, preserved 

 and mounted for the Microscope the adult which emerged and the 

 skin from which it escaped ; and I have also succeeded in mount- 

 ing specimens in the act of emerging, so as to preserve evidence of 

 the nymph being that of the adult to which it is assigned. When 

 I have not succeeded in breeding the species from one stage to the 

 other, I have omitted all mention of the nymph from this paper, 

 however strong the probability may be of the two creatures forming 

 the nymphal and adult stage of the same species. The single 

 exception to this rule is in the remarks made below as to the pro- 

 bable nyrnph of Nothrus j)ahistris ; these became necessary in 

 connection with another subject. 



Different Modes of carrying the Cast Dorso-abdominal SJcins. 



In studying the nymphs for the foregoing part of this paper, 1 

 have been much struck by the almost fanciful variety of the modes 

 in which they, and indeed the adults also, carry the cast skins. 

 The portion of the skin carried usually includes almost the whole 

 of the dorso-abdominal skin, and in every instance that I have seen, 

 it includes the posterior portion, but the mode of carrying varies 

 greatly, and is quite characteristic of species; the same species 

 always carrying them the same way. The skins do not split with 

 a ragged or destroyed edge, but quite evenly, and to a regular 



