1915] Muttkowski: Studies in Tetragoneuria (Odonata) 
61 
to the peculiar nomenclatural interchange in early descriptions, 
which have been variously followed by authors. In some cases 
the descriptions have been too inclusive. It is impossible to enter 
fully into a discussion of each reference; only the fact of inclusive- 
ness should be noted. 
The de Selys material under the head of cynosura appears to 
have its proper designation. Some of that under semiaquea ap- 
pears to belong partly to c. simulans, partly to semiaquea proper, 
although I am unable from the notes to say positively which is 
which. 
T. semiaquea. All of the material of de Selys under T. com- 
planata reverts to T. semiaquea; that under T. semiaquea, as stated 
above, is insufficiently diagnosed to permit accurate determination. 
It should be noted that it presents certain peculiarities, espe- 
cially exhibited by specimens from Massachusetts, which should 
make a detailed study of a long series from Massachusetts of 
’decided interest. 
Zoological Laboratory, 
University of Wisconsin, 
January 27, 1915. 
