150 Dr. T. A. Chapman on Heterogyna penella. 
modified, it gives us, I think, this information, otherwise 
unattainable, that not only are all the forward abdominal 
segments “free,” but the thoracic ones are so also. In 
the male pupa this is obscured by the appendages being 
partially soldered together, and fixing the body ; but with 
the information obtained from the female pupa it may be 
inferred that we are correct in regarding the opening of 
the thoracic incisions on dehiscence as a proof that they 
are not fixed segments. 
The resemblance to Psychids appears to be entirely 
superficial. The Psychids are clearly derived from a 
Tineid stirps and have a pupa associated with many Tineids 
in its amount of specialisation. Assuming a relation- 
ship of H. penella to Psychids, then it must have branched 
off before Psyche left Tinea, .c., before it had made the 
first steps to a vermiform female, before in fact it was a 
Psyche. On the other hand, the larval prolegs show that 
Heterogyna has been an external feeder, at least, for a long 
time, and in this respect it is as much above Psyche, as 
pupally it is beneath it. In other words, we have to go 
a long way outside the Psychids to find a common point 
of relationship; or, in the usual way of expressing such a 
degree of relationship, there is no relationship at all, that 
is beyond their both being somewhat generalised forms in 
many respects. 
