Revision of the Notonectide. 413 
p. 70). From the description, the latter is evidently a 
Coriva, as, presumably, is also N. noveboracensis, Gmel. 
The variations in N. wndulata in the colour of the 
abdominis dorsum and venter are irrespective of hemiely- 
tral pattern and coloration ; the variations in the colour 
of the scutellum are, to a certain extent, regular. Var. | 
has a luteous scutellum always; vars. 2 and 3 luteous, 
black, or variegated ; vars. 4 and 5 only black ; var. 6 
luteous or black. 
9. Notonecta bifasciata, Guér. 
Notonecta bifasciata, Guér., 1835, Icon. R. Anim., 
. d04, 
N. polystolisma, Fieb., 1851, Abh. bohm. Ges. Wiss. 
(5), vu., p. 477; Berg., 1879, Ann. 8. Cient. 
Argent., vii., p. 75 (reprint, p. 198). 
Head : notocephalic lateral margins diverging curvedly from the 
narrow base, vertex about three times as wide as synthlipsis. Pvo- 
notum : humeral angles acute, accentuated, humeral margins sinuate, 
about subequal to lateral margin, posterior margin sinuate, width 
about two and one-seventh times as great as the length of the 
pronotum. Hemielytra varying much as in NV, undulata. Alar 
nervures pale golden yellow. Pedes: intermediate tibial spur 
small. <Abdominis dorsum black, genital segments testaceous. 
Abdominis venter castaneo-testaceous spotted with black, 
Long. 8°6—9 mm., lat. 3-3°2 mm. 
Types : bifasciata, Guérin-Ménéville colln. (Mus. Paris) , 
polystolisma ? 
Hab. S. America. Apparently distributed over the 
greater part of Brazil, and the Argentine and Uruguaian 
Republics. I have given a very brief description of this 
species, as I am uncertain of its limits, and have had 
very little material to work on. Guérin’s type (possess- 
ing violet-black hemielytra with a broad ivory-white 
band along the whole of the corial margin, and two 
orange spots uear the apical margin of the corium) is 
stated by Guérin-Ménéville himself to be the same as N. 
polystolisma, Fieb., and accords well enough with the 
description. ‘The type bears two written labels, the first 
and older, ‘‘ Notonecta bifasciata, Guér., Ic. R. A. Plata 
TRANS. ENT. SOC. LOND, 1897.—PaRT Iv. (DEC.) 28 
