412 Mr. G. W. Nirkaldy on the 
(except the wide black sutural margin) and a small blotch 
on the corium, dirty white; apical portion of membrane, 
and a large spot about the middle of the apical margin 
of the corium, castaneous. Scutellum black (Paris, 
Stockholm, and Vienna Mus.; Montandon’s coll.). 
Types. N. undulata, Say, punctata, Fieb.? N. vires- 
cens, Blanch., Paris Mus. 
Hab. N. and C. America; S. America, North of 
Patagonia. ANTILLES. 
Var. 1. New Jersey and Maryland (my coll., Prof. Uhler), 
€Cuadeloupe (Noualhier and Montandon colls.), Colombia (Paris 
Mus.). 
Var. 2. Canada (Provancher), Winnipeg, Valley of Mackenzie 
River, etc. (Uhler in litt.) ; the whole of the U.S.A. ; Mexico ; 
St. Bartholomew, Jamaica ; Cuba (Paris Mus.) ; Colombia, ete. 
Var. 3. Most of the U.S.A., but local; Cuba ; Mexico; Colombia 
(Paris Mus.) ; Peru (Hamburg JMus.). 
Var. 4. Baltimore (Fveber), Sabillasville, nearly 2000 feet above 
sea level (my coll., Prof. Uhlev), South States (UWhler) ; New 
Orleans (Paris Mus.). 
Var. 5. Chili. 
«This species inhabits the foulest pools, and in the 
dirty slush occasioned by the drainage of slaughter- 
houses, and in the slimy ponds attached to some of our 
brickyards, it revels as if in full enjoyment of the filth” 
(Uhler). Prof. Uhler also writes to me: ‘‘ Water of 
high temperature (i.e., exposed to the sun’s continuous 
rays) gave me N. wndulata, Say, in many conditions.” 
(See also NV. insulata for further notes.) This species is 
very similar to N. glauca, L., and it is difficult to diffe- 
rentiate them by words. N. widulata is always smaller 
and more triangular, and (though this is not always the 
case) the humeral margin does not seem to be so dis- 
tinctly separated from the posterior margin of the pro- 
notum as in N. glauca; the base of the pronotum thus 
acquires a more convexly curved and rounded appearance. 
The luteous examples of var. 5 are labelled in several 
collections “ noveboracensis, Forst.”” There is, however, 
no Notonecta noveboracensis, Forst. Gmelin (1789, in 
Linn. Syst. Nat. xii., p. 2119) by error substituted this 
name for N. lineata, Forst. (1771, Nov. Spec. Ins., i., 
