BY R. J. TILLYAKD. 25F) 



neither of the two Orders Protoraecoptera and Paramecoptera 

 can be derived from the other. A more archaic type of Holo- 

 metabolon must have existed, somewhere in the Permian, which 

 possessed the archaic characters of both; and this insect would 

 also have possessed the archaic characters of the Mecoptera. In 

 other words, the three Orders Mecoptera, Paramecoptera, and 

 Protomecoptera are to be regarded as bjeing collaterally related, 

 all three being separately derived from a single, more primitive, 

 Holometabolous stock. In constituting three separate Orders 

 for these three types, I have followed the wise precedent of 

 Handlirsch in similar cases; since only by this method can the 

 essential differences between them be sufficiently emphasised. 

 Further discoveries at Belmont or Ipswich may perhaps enable 

 us to place all these types definitely within a single enlarged 

 Order Mecoptera, from which all the other Orders within the 

 Panorpoid Complex have probably been derived. 



We may sum up the evidence as to the affinities of this inter- 

 esting new fossil Order by saying that it has now been shown to 

 be definitely ancestral to the Trichoptera and Lepidoptera, but 

 of collateral descent with the Mecoptera and Protomecoptera. It 

 may verv possibly be ancestral also to the Megaloptera and 

 Planipennia. With the Paratrichoptera and the Diptera it is 

 not possible, so far, to determine the nature of its affinity, though 

 there is no doubt of a relationship of some kind between them, 

 probably through the Mecoptera. If the only types of Holo- 

 metabola existing at Belmont be Mecoptera and Paramecoptera, 

 then the probability that all other Orders within the Panorpoid 

 Complex are descended from one or other of these two, or from 

 the Protomecoptera of the Trias, would be very great. Thus we 

 leave this interesting problem, in the hope that further dis- 

 coveries from the Belmont Beds may yet clear the whole matter 

 up, and settle the descent of all these Orders without any doubt. 



