CLASSIFICATION OF THE PSYCHIDES. 127 



line than i, the female pupa-skin remaining within the case, whilst the 

 $ imago emerges and remains on the outside of the case to oviposit, 

 after the fashion of the Taleporiids, although its abdomen is partly 

 inserted in the case during the operation. At the same time, the habit of 

 covering the case with larger pieces of lichen, leaves, grass-stems, &c, was 

 originated. Considerably above these the Epichnopterygids branched 

 off, and these have, in almost all their characters, distinct suggestions 

 of the higher Psychids. It may appear rather strange to say so, but 

 one is compelled to conclude that the latter are almost unknown, so far 

 as their relationships to each other are concerned. We do not wish to 

 underestimate Heylaerts' subdivisions based on the neuration, but so 

 far as our study of the life-histories of a few species has gone they are 

 evidently quite inadequate. It is clear that our British species belong 

 to different genera, Avhilst unicolor, atra, and others that have been 

 carefully examined, belong equally to different genera, yet Heylaerts 

 includes two species so widely different, structurally, as unicolor and 

 villosella in a single genus. In speaking, then, of the higher Psychids 

 (i.e., Macro-Psychids) we are on safe ground, as it does not involve a 

 theory of relationship of families to each other, and this is our reason for 

 using the term so frequently in this chapter. The Oiketicidae, the 

 Paychidac, the Caneplwridae ; and Apteronidae of Heylaerts all represent, 

 apparently, primary divisions of the higher Psychids, and it is only a 

 matter of terms as to whether they be called families or subfamilies. 



We may perhaps illustrate our idea of the relationship of the 

 Psychid families occurring in Britain by means of a phylogenetic tree 

 (Plate ii). Taking this tree as a basis of classification we have (1) the 

 Micro-Psychids — consisting of the Naryciidae, Diplodomidae, Talepori- 

 idae, and Solenobiidae, in which the $ and ? pupal skins are both left 

 protruding from the larval case after emergence, the eggs laid in the 

 larval case (not in the pupa-skin), the larva with the dorsal tubercles 

 i and ii trapezoidal (i nearer median line), the pupa in both sexes with 

 the two dorso-anal spikes, and the imago Avith generalised Tineid 

 characters. (2) The Maceo-Psychids — consisting of the Fum.eid.ae, the 

 Epichnopteryyidae, and the Psychidae. These have the 5 pupa-skin 

 retained within the larval case on emergence ; the eggs are laid within 

 the pupa-skin, in a more or less agglomerated mass ; the larva has the 

 dorsal tubercles i and ii arranged so that ii is nearer median line than 

 i ; the pupa is Avithout the dorso-anal spikes, but has tAvo A'entro-anal 

 spikes (modified anal legs of larva), and there is a posterior row of 

 intersegmental hooks on certain of the abdominal segments. 



The Liiffiidae are intermediate in their characters. The egg-laying 

 habit, retention of ? pupa-skin Avithin the larval case, and the 

 arrangement of the larval tubercles i and ii, are Macro-Psychid, Avhilst 

 the case and the general structure of the pupa are Micro-Psychid ; the 

 2 also has Avell-developed legs, leaves the case, pairing outside and 

 laving her eggs Avith a highly specialised Taleporiid OA'ipositor. The 

 Fumeidae, although shoAving absolute Macro-Psychid characters in the 

 mode of egg-laying (within the pupa-skin), and in larval and pupal 

 structure, have a, female with powerful legs, that leaves the case and 

 is provided with a Taleporiid ovipositor. These two families, therefore, 

 show that there is no distinct break between the Macro- and Micro- 

 Psychids, socalled, but that a sIoav process of evolution has taken place 

 from the most generalised to the most specialised forms. 



