HUNGERFORD: AQUATIC HEMIPTERA. 155 
more convex than with the true R. quadridentata Stal., the cheeks: sen- 
sibly more elongated and more prominent in front of the eyes, subparallel, 
a little attenuated in front, but not divergent at the summit, better 
applied against the tylus, which surpasses it, also very sensibly in front, 
which gives to the anterior part of the head a form a little more elongate 
in front of the eyes. 
“Pronotum very visivly narrowed in the middle, enlarging insensibly in 
the rear and in front. This character permits one to distinguish quite 
easily this form from the true R. quadridentata Stal., with which the 
median constriction of the pronotum is a great deal less marked (assuse) 
and the anterior part more cylindrical. 
“The majority of the examples of this species have the double tooth at 
the extremity of the anterior femur, which has confused it with the 
true R. quadridentata Stal.; but this double tooth is often very attenu- 
ated and sometimes even altogether atrophied. I have distinguished 
this latter example under the name of R. americanus var. edentula. It is 
represented in my collection by two single female examples, one from 
Pennsylvania, and the other from Texas.” 
Bueno, in his “Three Ranatras of N. E. U. S.,” states that the legs of 
R. quadridentata are not unduly long, the tarsal claws of the third pair 
barely going beyond the middle of the air tubes, and the extremity of the 
femora going but little beyond the anterior margin of the penultimate 
abdominal segment. The eyes moderately large and the prothorax more 
stoutly built and bisulcate beneath. 
Ranatra brevicollis Montd. 1910. 
Montd. Bul. Soc. Sco. Bucarest, XVIII, p. 184. 
“It is indeed regrettable that I have described this new form from one 
unfortunately unique specimen, very little dissimilar, at first sight, from 
R. quadridentata Stal., but its specific characters do not permit it to be 
confused with the other species, fusca or quadridentata, from which it 
differs by its anterior femora being very slightly sinuate toward their ~ 
extremities. It also has a single tooth before the median sinus of the 
femur. A little more thick-set, of form less elongate than R. fusca Pall 
de B., which would bring it closer to R. quadridentata Stal. It is sep- 
arated as plainly from this latter form by the much shorter form of the 
pronotum. In fact, the insect is 34 mm. long, of which length the head 
and pronotum have only 10 mm. The appendages of 22 mm. are sen- 
sibly shorter than the abdomen. The intermediate and short posterior 
femora, folded forward, scarcely surpass the head. 
“The pronotum very robust, about a third as long as the abdomen, 
quite strongly dilated in front, and very strongly enlarged behind, does 
not allow confusion with R. kirkaldyi T. B. It is, besides, marked by two 
longitudinal grooves, slightly oblique on the sides, behind the anterior 
dilation, not attaining behind the transverse grooves which limit in 
front the posterior dilated part of the pronotum. This latter marked 
by a longitudinal median carina disappearing behind, less emphasized 
in front, where it traverses the transverse groove which limits the 
posterior dilated part. 
“The legs are very slender, a little shorter proportionally than those 
of R. quadridentata Stal.; femora reddish, marked by pale, wide, little 
visible annulations. 
“Metasternum in a plate (metasternal plate) terminated in the middle 
behind by a narrowed prolongation between the posterior cox, appear- 
ing more elevated than in R. fusca P. de B. and R. quadridentata Stal., 
but less, however, than in R. fabricii Guer.-annulipes Stal. 
“This species, however, is distinguished from the three other known 
