1915] Muttkowski: Studies in Tetragoneuria (Odonata) 
59 
williamsoni MUTTKOWSKI, Bull. Wis. N. H. Soc., (2) 9, pp. 95, 122, 
1911 : 9 & desc., types Coll. Williamson and Milwaukee Mus.; 
t. f. 4, c? $ char.; pi. 6, wings. 
Distr. Austroriparian, ? Okl. 
NOTES ON SYNONYMY 
A few notes on the synonymy are taken up in alphabetical 
order. In addition the specimens of the de Selys Collection 
which have formed the basis of so many of the species of the 
genus are referred to the species they appear to belong to; in this 
I am guided solely by Dr. Ris’ excellent notes on the specimens 
in the Brussels collection, these notes being for the greater part 
sufficiently detailed as to color markings to permit of fairly 
accurate determination. 
T. basiguttata. The reference of this form to cy nosura is based 
on Dr. Ris’ notes. The de Selys Collection contains two males, 
labelled: 1. Cord, complanata (Coll. Serville) Gold; 2. (L. com- 
planata/Amer. sept./ Coll. Latreille/gold) . Surely these are hardly 
in accord with the statement of de Selys (1871): “Le male de 
la Floride, (coll. Selys); la femelle de Conton, pres de Boston.” 
The female mentioned by de Selys is without doubt a true cyno- 
sura, while the male from “Floride” may belong to some other 
species, possibly stella. The two specimens listed by Ris are 
cynosura. 
T. cams, costalis, spinosa, and spinigera (Selys $ 1874). This 
is one of the puzzles of the genus. Through some peculiar adver- 
sity of fate I have been unable to obtain entire females of the 
species cams and spinosa. T. costalis was described from a single 
female now in the British Museum. A complete description by 
Kirby of this individual was quoted on page 132 of the “Studies.” 
The true spinosa, both male and female, seem practically absent 
from American collections; nevertheless, there can be no doubt 
of the identity of at least the male. 
Two males quoted by r Martin (1907) in the de Selys Collection 
as T. costalis are T. cynosura. Dr. Ris has this to say about the 
specimens: “Clearly, these two specimens are not in the least 
very different from the cynosura male of the collection. It is 
not evident if they have been classed as costalis by de Selys al- 
ready, or afterwards by Martin, or (perhaps this is the most 
