NATURAL SCIENCES OF PHILADELPHIA. 45 



which subsist between certain existing Lepidoptera and Trichop- 

 tera, both internal and external, in their three stages of existence 

 as larvae, pupae, and imagos ; and, lastly, their remarkable simi- 

 larity of habits. 



In commenting upon the first consideration, it strikes me as 

 peculiarly novel and remarkable, that such delicate creatures as 

 Tineids should be preserved in association with Sphinges, there 

 not being the remotest affinities between them, while the interme- 

 diate types, if there are any, which palaeontology alone must de- 

 cide in the future, should have left not even the slightest evidence 

 of their existence. 



A few thoughts having reference to the second consideration, 

 lead to more important results. The great abundance of Neurop- 

 terous life, both high and low, that existed during the Triassic 

 and Jurassic epochs, backed up by the third consideration which 

 shows that notable affinities exist between certain forms of Lepi- 

 doptera and Phryganea, seems to argue strongly in favor of the 

 theory that the Jurassic sphinx was the remote modified descend- 

 ant of some pre-existent Caddice fly, which latter was the offspring 

 of some formerty-existing Neuropter. 



The Tineids of to-day are, as a general rule, but diminutive 

 specimens of lepidopterous life, notable alike for their inconspicu- 

 ousness and insignificance. Rarely if ever attaining any remarka- 

 ble development of size, they, doubtless, have retained much of their 

 primitive character. Like some forms of Terebratula, as before 

 remarked, they have maintained the even tenor of their lives 

 doubtless for ages. Natural selection has had little play in the 

 line of variation in this family. It has been affirmed that the 

 Caddice worms construct cases like the larvae of Psyche and 

 Tinea, which they line with silk. Fi'om this it is argued that 

 Psyche and Tinea have been evolved from some form of Phryga- 

 nea, and that the Sphinges have come through the former. But 

 this does not necessarily follow. May not the Phryganidse have 

 been the common stock of both Tineids and Sphinges, the latter 

 being a more highly specialized type, from having been reached 

 through greater and more persistent modifications ? Perhaps there 

 were existing in those remote ages many forms of Phryganidse 

 differing greatly in size, but still retaining similarity of habits. 

 Granting this, for the sake of argument, there can be no impro- 

 priety in considering the Tineids to have been the immediate de- 



