Revision of the Notonectide. 4.09 
in N. undulata, Say. Hemielytra variable: (1) fulvous or dark 
stramineous, with a broad black fascia near the apex, occupying 
the basal two-thirds of the membrane, and the apex of the corium. 
This seems to be the original N. americana, Fabr, (2) Varying 
from bluish-black to violet-brown ; the corial margins of the 
clavus, and a broad irregular blotch about the middle of the 
corium, fulvous or dark stramineous. Otherwise like N. wndulata, 
Say. 
Long. 10-11 mm., lat. 3°5-3°6 mm. 
Hab. ©. and §S. America, Mexico (Puris Mus. ; 
Noualhier and my colls.); Chih, Valdivia (Hamburg 
Mus.) ; Cuba (Paris Mus.; my coll.). It probably extends 
over Mexico, the Antilles, and the greater part of S. 
America. 
This species has been compared with N. widulata, Say, 
instead of the reverse, as, through the kindness of Prof. 
Uhler, I have had plenty of fresh material in the latter 
species, whilst in the present species I have only seen 
two fresh specimens (from Prof. Uhler). Fabricius says 
“alis nigris”’-—but the few examples I have been able to 
examine have transparent, colourless alee with nervures 
coloured as in N. undulata, though Prof. Uhler writes 
me that he formerly possessed at least two specimens 
with the exterior margin of the alee black. Hoping that 
the Copenhagen Museum might possess Fabricius’s 
missing type, one of the above examples was sent to Dr. 
Meinert, who wrote that he had compared it and found 
it to accord with a specimen labelled “ N. americana” 
which was undoubtedly seen by Fabricius, though it is 
not the type. ‘This and the two following species Prof. 
Uhler considers as most probably conspecific, and it is 
probable that future researches will show this to be so ; for 
the present, however, it seems best to regard them as dis- 
tinct. In his N. americana Fabricius probably also included 
N. undulata, Fieber’s N. variabilis undoubtedly included 
N. americana and N. wndulata, while Say’s N. widulata 
included N. americana and probably N. variabilis ; and 
the references given to all three species must therefore 
be taken as the best possible under the circumstances. 
N. americana, Herr.-Schiiff., is clearly N. undulata, from 
the figure, and N. variabilis, Guér., is the same species, 
according to the specimens labelled by him in his 
collection (Paris Mus.). 
