MICRO-PSYCHINA. 133 



although the strong hooks enable them to cling most tenaciously to the 

 inside of the case. The true legs, on the other hand, are very strong 

 and powerful. The thoracic segments are covered dorsally with 

 corneous plates, the abdominal segments are soft, bulky, and with a well- 

 developed lateral flange. The arrangement of the dorsal tubercles shows 

 a complete system of evolution with regard to position, from the 

 ordinary trapezoidal form with i nearer the median line than ii (Narycia, 

 Diplodoma, Solenobia) to a form with ii directly behind i (Bankesia, 

 Taleporia), thence ii passes much nearer to the median line than 

 i (Lutfia, Bacotia), and thus reaches the peculiar but normal Macro- 

 Psychid arrangement for these tubercles ; the other tubercles are 

 characteristic, in position, of the other superfamilies of this stirps 

 (except the Sphingids), viz., iii supraspiracular, iv and v subspiracular 

 (iv with strong, v with weak, seta), vi below these, and vii marginal, 

 each tubercle consisting of a minute chitinous button with a single 

 seta. The arrangement of the crochets of the prolegs are charac- 

 teristic — horseshoe shaped (or an oval broken on the inner edge). 



We are informed by the authorities, and it is probably true, that 

 the larvae 'of the Micro-Psychids live on lichens that grow on fences, 

 trees, rocks, &c. In the case of some genera we are inclined to doubt 

 whether this is the whole truth, and should not be surprised to find 

 that the larva? of Taleporia and Diplodoma are more or less scavengers 

 on the ground, going to fences and tree-trunks only for the purposes 

 of exuviation and pupation. This also is possibly to a certain extent 

 true for some species of Solenobia. At any rate, in confinement, the 

 larvae of T. tubulosa (pseudobombycella) and D. herminata (inarginepunc- 

 tella) are well known to be carnivorous under certain conditions. It 

 is, of course, possible, that larvae, living on lichens growing on damp 

 Avails, fences, &c, require much moisture, and their confinement with 

 a piece of food-plant liable to get out of condition, leads to an exhi- 

 bition of carnivorous propensities. The enclosure in cramped 

 quarters and the drying- up of food are known to develop cannibalistic 

 tendencies in certain larvae (Asteroscopus sphinx, &c.) and this may be 

 a parallel instance. 



The pupa of the Micro-Psychids is very characteristic. One 

 peculiar feature is the arrangement and development of the various 

 pupal mouthparts (especially in the females), and there is no doubt 

 that a close study of these, the pupal antennae, and the wings, would 

 give some important facts bearing on the evolution of the helpless 

 egg-sacs into Avhich the females of the Macro-Psychids have been 

 specialised. Other peculiarities are the presence of two minute dorso- 

 anal points in both sexes (except the Lufliids, in the females of which 

 they are absent), the modification of some (or all) of the setae on 

 abdominal segments 7-10 into long recurved hairs, the presence of a 

 patch of short spiny hooks on the anterior portion of abdominal 

 segments 3-7, the scars of the anal prolegs, and the reproduction in 

 detail and position of the larval tubercles and setae. That the dorso- 

 anal hooks and recurved setae function largely in restraining the pupa 

 at the proper point of protrusion from the larval case for the emer- 

 gence of the imago is obvious, but we doubt whether the former are 

 homologous with the anal leg-hooks, as Packard says, although there 

 can be no doubt that the ventro-anal hooks of the Macro-Psychids 

 are to be so homologised. 



