374 BRITISH LEPIDOPTERA; 



does our present knowledge enable us to offer any serious criticism to 

 this scheme. One might object that, although the subfamilies are 

 defined on antennal and tibial structural peculiarities, the tribal sections 

 are separated on neurational characters, but it must not be overlooked 

 that the same division has been made (ante, p. 274) on other grounds. 

 So far as the Oiketicids and Acanthopsychids are concerned, one is led 

 to suppose that Chapman is quite correct, at least an attempt to sum 

 up the characters presented by these, shows much in favour of his 

 view. The common characters presented by the antenna (ante, p. 

 273), the anterior tibial spurs (ante, pp. 273, 274, 275), the presence 

 of well-developed wing-scales (ante, p. 274), the development of supple- 

 mentary wing nervures (ante, p. 275), and the not yet complete loss of 

 the posterior tibial spurs (ante, p. 271), form an accumulation of 

 details that unite the Oiketicids and Acanthopsychids, and separate 

 them from the Psychids (i.e., the Empedopsychids and Oreopsychids). 

 Such an array of facts it would be idle not to recognise. One regrets 

 not to be able to support them with characters drawn from the early 

 stages, but, as Ave have already stated, our knowledge of these is as 

 yet too imperfect to allow us to satisfactorily attempt the task. One 

 suspects, however, that the Oiketicids are more generalised than the 

 Acanthopsychids (ante, p. 274). This view would appear to be sup- 

 ported by the peculiarities exhibited by the better scaled antennae, by 

 the presence of the cellula intrusa, by the broader and generally less 

 hair-like scales, by the somewhat less delicate condition of the ova, and 

 the plentiful supply of soft silky hair* in which the ova are embedded 

 (Ent. Rec, vii., p. 123), a fact that suggests some marked constitutional 

 difference in the females. With regard to the subfamilies into which 

 the Psychidae are here divided, we have no Oiketicids in Britain, two 

 Acanthopsychids, one Psychid, and no Oreopsychid. None of the, 

 known species of Apterona (helix, ? helicinoides, eremdella, gracilis,, 

 jmsiella) are found with us, so that our native list is a very poor and 

 meagre one. Whether the Psycheoidids belong to this, or form a 

 separate family, we are not in a position to judge, but Heylaerts 

 excludes them, and gives them a rank equal to our Pxychidae. He 

 defines the group as follows : 



Les ailes anterieures ont deux internes separees, dont la superieure est tres 

 mince. La dorsale ne se bifurque pas. Point de cellule interposee ou il y en a une. 

 Les tibias posterieurs ne portent qu'une seule paire d'eperons plus ou moins 

 prononces Psycheoidina, Heyl. 



Explanation of Plate V. 

 Thyridopteryx ephemeraeformis presents in most of its characters 

 well-marked and typical Acanthopsychid features. Its life-history, 

 already referred to (ante, pp. 368 et seq.) was worked out by Eiley,. 

 to whom we are indebted for the figures represented in the plate.. 

 These are : — 



Fig. 1. a. Case showing ? at entrance. 

 b. Female much enlarged. 



Fig. 2. b. End of male abdomen show- 

 ing, k-i, the detailed parts of 



* Smith notes the eggs of Thyridopteryx ephemeraeformis as being surrounded 

 by a delicate fawn-coloured, silky down. Kirby also observes that the ? ofr 

 Oiketicus kirbii covers her eggs with down from her own body. 



male genitalia when extended. 

 c. Genitalia from below, d. Geni- 

 talia from above. 



