ORIGIN OF LEPIDOPTERA. 3 



orders are not only very closely allied, but even that they may have 

 originated from a common ancestry, the loss of thoracic, and of 

 abdominal, limbs, and the reduction of the head and its appendages in 

 dipterous larva?, as well as the reduction of the hind-wings, being due 

 to modification from disuse. In the dipterous pupa, as exemplified 

 by Gulex, the hind pair of wings is nearly as well-developed as are 

 those of lepidopterous pupae. 



There appear to be many Neuropteroid characters in the imagines 

 of the more generalised Lepidoptera, and these have been, of course, 

 those from which the phylogeny of the order has been principally 

 studied. There are the square head, the small eyes, the vestigial 

 mandibles ; the retention of the maxillary palpi, and of the lacinia 

 and galea (or rather the homologues of these in the form of the 

 maxillary lobes) in the Eriocephalides ; the large meta-thorax with 

 separate scuta, the exserted large male genital armature of the 

 Micropterygides and the Psychides ; the Trichopterigiform neuration of 

 Hepialids and Eribcephalids, etc. As we pass from the more genera- 

 lised to the more specialised forms of Lepidoptera, these characters 

 become exceedingly modified, and are often entirely lost. 



We have before pointed out that Speyer was one of the first to show 

 the resemblance of the Hepialid, Cossid, Micropterygid and Psychic! 

 neuration to that of the Trichoptera. He also pointed out the fact 

 that there were certain Lepidoptera — Heterogenea, Aclela, Micropteryx — 

 whose pupa? possessed free limbs, and also that certain species of both 

 orders spin a cocoon. Speyer, however, was inclined not to consider 

 the Lepidoptera as descending directly from the Trichoptera, but that 

 both had a common origin, the latter being the first to appear, and 

 that the common ancestor probably had an aquatic larva. He further 

 noticed that their mouth-parts were, in reality, very similar. The 

 close relationship between the Trichoptera and Lepidoptera was also 

 shown by Miiller, who claimed that there was the closest affinity 

 between the Phryganeidae and the Lepidoptera, and that both had 

 proceeded from a common stock. Packard, however, shows* that 

 there is considerable difference between the mouth-parts of the two 

 orders, and concludes that, with respect to the structure of the 

 maxillae, the Lepidoptera are nearer the ametabolous mandibulate 

 insects than the Trichoptera. 



The same author also compares the neuration of the Eriocephalides 

 and the Micropterygides with that of Amphientomum, a generalised 

 Psocid, and he considers it " not impossible that these insects, with 

 their reduced pro-thorax and concentrated or fused meso- and meta- 

 thorax, together with their maxillary fork, may have had some 

 extinct allies, which were related to the remote ametabolous ancestors 

 of the Lepidoptera." 



Hermann Miiller has also suggested a close relationship between 

 the Tipulariae, the Lepidoptera, and the Phryganeiclae, and compares 

 the similar neuration of Limbnobia and Ctenophora with that of the 

 Phryganeids, and states that "it is far easier to deduce morphologi- 

 cally the proboscis of the Tipulae from the buccal organs of the 

 Phryganeidae than from those of any other order of insects." 



Chapman's studies of the pupa have led him to make some im- 



* Bombycine Moths of America, 1895, p. 55. 



