:;12 THE CANADIAN ENTOMOLOGIST. 



Mesoveliidce also, but not to as great a degree. I do not believe that the 

 sericeousness of the underbody is necessarily an indication of adaptation to 

 an aquatic or semiaquatic habitat, because we can see this in many land 

 forms, especially among the Lygceidce (of the older authors, not of 

 Kirkaldy). Nor is ability to walk on the surface a sign of this peculiar 

 fitness, because there are other forms, such as some Diptera, a few 

 Hemiptera (Heteroptera and Homoptera), etc., which walk on the waters 

 at a pinch, and this last is what Mesove/ia does. Under compulsion it 

 runs rapidly out upon the water from its habitual and customary haunts 

 on floating vegetation (Alga?, Duckweed, etc.). Hydrometra also hugs 

 the shore, and it does not appear to go any very great distance from land. 

 Now, the true Gerridce are bold navigators, and put out fearlessly upon 

 the bosom of the deep, with which they are eminently fitted to cope. 



But on the whole, Kirkaldy's paper is highly suggestive and ought to 

 lead to a careful re-survey of the whole subject of the classification of the 

 Heteroptera, so sadly neglected by competent observers, even unto this 

 day. Nothing short of a drastic revision of the whole Order will avail us. 



NOTES ON PACHYBRACHYS AND DESCRIPTIONS OE NEW 



SPECIES. 



BY FRED. C. BOWDITCH, I'.ROOKLINE, MASS. 

 (Continued from pa^e 292.) 



PachybracJiys nubilus, nov. sp. — Medium sized, cylinder shaped, 

 shining, light yellow, with indistinct livid spots ; finely punctate with well- 

 marked elongate triangular shield. Length, 2^ mm. 



Head convex, yellow, a faint tinge of livid on the vertex and a very 

 fine well-marked central line and two small spots at the roots of the 

 antenna?, which are yellow, becoming darker towards the end, and reach 

 about the middle of the abdomen ( o" ), eyes distant ; thorax yellow, 

 proportionally long, very slightly narrowed towards the front, punctuation 

 rather coarse and thick, antescutellar lobe well marked, the posterior edge 

 thickened on either side, M faintly indicated in livid, sides lightly 

 angulate ; elytra parallel, yellow, with brown punctures \ of about the 

 same width as the thorax, standard spots diffusely indicated in livid, 

 punctures confused in the scutellar area, the third, fourth and fifth intervals 

 are fairly regular, and then the sixth and following are broken up to the 

 two side intervals, all the costse are well marked and nearly regular on the 

 convexity ; there is a well-marked elytral shield, triangularly elongated in 

 the rear, and the rear portion forms part of a line of yellow spots which 



September, 1909 



