HUNGERFORD: AQUATIC HEMIPTERA. 201 
“Texas, Belfrage U. S. N. M., Washington and my collection. 
“This species in its form typical, of deeper color, is without any doubt 
very close to A. nitidulus Montand, 1909, of Mexico. However, the corium 
appear always sensibly less developed. and the punctation of the anterior 
angles of the pronotum less accentuated.” 
Ambrysus circumcinctus Montd. 
Montandon, Bul. Soe. Sci. Bucarest, XIX, No. 3, p. 5, 1910. 
“Form oval, hardly more attenuated in front than in the rear. Colora- 
tion dull uniformly yellowish on head and pronotum, a little infus- 
cated on the scrtellom and the elytia. Length, 8 mm.; head medium 
rather weak, with the eyes quite convergent in front for almost their 
entire length, the convergence a little less accentuated behind. Anterior 
border of the head quite regularly arcuated and very narrowly blackish 
at the tip. which margin is notably anterior to the level of the e es. The 
head above, at least, as long as broad, between the eyes behind, about 
three times wider between the internal posterior angles of the eyes than 
the width of the eye at the same level; posterior portion of the head 
sunken into the median incisure of the pronotum, visibly longer than the 
anterior portion behind the eyes; punctuation of the head very fine, 
rather dense, but irregular and inconspicuous. Hardly a little more 
accentuated near the eyes and in front. Vertex uniformly pale without 
apparent markings. 
“Pronctum with lateral margins feeblv but rather regularly arcuated 
and. divergent behind for almost their entire length, save in region of 
the posterior angles where they are narrowly subparallel. The angles 
are almost right, or a litt’e obtuse, and slightly rounded at the summit. 
The lateral margins are very narrowly blackish on their extreme lateral 
margin. Anterior angles of pronctum rather acute but not arcuate at 
the summit. Anterior margin of pronotum profoundly incised. The 
transverse median incisure is rather large, but quite profound, the 
lateral incisures well accentuated behind the e es. They are, however, 
a little less transverse than in A. pulchellus. The entire surface of pro- 
notum rather uniformly yellowish, hardly paler on the narrow pos- 
tericr portion, a little depressed but without an apparent furrow, the 
denression almost lacking in the middle. Punctuation very fine, rather 
dense and irregular over the entire surface. Median sinuosity bordered 
bv a weak margin less accenuated and with very fine and superficial 
transverse wrinkles, that are not very visible, behind the middle of the 
anterior border without apparent depressions, a!though this median por- 
tion may te visibly limited on each side by a slight]: depressed oblique 
line, irregular, appearing a little ‘posselee.’ 
_“Scutellum slightly and rather uniformly darkened, with the basal 
angles and the summit paler, unpolished with the surface very finely 
granulated. 
“Corium quite uniformly pale brownish. having the scutellum and 
embolium in large part pale, the external margin very narrowly blackish, 
slightly areuated;*margin of corium behind the embolium very obtusely 
sinuated. Commissure of the clavus narrowly pale, near the middle 
shorter than the length of the scutellum; posterior margin of the corium 
with a semi-cirenlar yellowish spot. Disc of the corium appearing cov- 
ered by a very fine pubescence almost clear. Membrane brownish con- 
colorous with the corium. 
“Segments of connexivum plainly visitle behind the narrow elytral 
margin; unpolished, yellowish, without spots on the sutures, but with the 
extreme outer margin very narrowly blackish; posterior angles of the 
segments not projecting, following well the abdominal curve except on 
the last segment, whose angle is a little prolonged behind, but scarcely 
acute at the tip on each side of the female genital pieces. 
