88 THE UNIVERSITY SCIENCE BULLETIN. 



black, minutely sericeous pubescent, with a slender black stripe along 

 the middle. Length to tip of venter, 2i/4-2V^ mm.; width of pronotum, 

 1 mm. 



"Three specimens of this insect were captured on the Mount Gay 

 estate and Balthazar in June and August. During the latter month they 

 occurred at the roots of grass, on muddy ground near pools of water. 

 This species is a common one which has been met with in the Atlantic 

 states and the West Indies, and it also occurs in California and Wash- 

 ington states. In Maryland it lives on the damp sand or mud of small 

 pools beside streams of water, in spring and late summer. The unwinged 

 individuals may be found skimming over the surface of quiet water 

 from spring until the end of summer." 



Localities: Quebec, Ontario, New York, New Jersey, Pennsylvania, 

 Maryland, Florida, Illinois, Colorado, California and Washington. 



B. Biology of Hebrid^. 



General Notes These small, plump-bodied insects live about the mar- 

 gins of pools and upon the floating vegetation. They are predatory in 

 habits. 



Genus MERRAGATA White. 



Little or nothing is known of their life history. 



Carl Drake says that those he has studied "are dwellers in still and 

 stagnant waters. Their favorite haunts are secluded coves of lakes, 

 ponds, and swampy pools, where the water is shallow, and where there 

 is an abundant growth of aquatic plants. I have rarely seen them on 

 the damp ground near the water's edge. The Merragatas are aquatic 

 pedestrians, capable of standing, walking, and running upon the surface 

 of the water, their entire body being covered with a velvety pile which 

 effectively sheds the water and prevents them from becoming wet. They 

 can move forward or backward, but the usual mode of progression is a 

 steady forward movement, all three pairs of legs being used in locomo- 

 tion. I have often found them on Lemna, Nymphaea, and various other 

 aquatic plants. It is not uncommon to find them on the underside of 

 floating leaves, or even among the roots of floating water plants. When 

 submerged in the water, the insects are surrounded by a film of air 

 which enables them to stay beneath the surface film for a considerable 

 period of time. In an aquarium I have often watched them standing 

 or walking for a period of a half hour or a little longer on pieces of 

 cork or plants that were beneath the water. Occasionally, they will 

 walk down the sides of the glass aquarium beneath the surface of the 

 water, and when the water is shallow, they will walk across the bottom 

 and come up on the opposite side." 



Genus HEBRUS Curtis. 



These insects are to be found in the midst of moss clumps and shore 

 grasses by the water's edge and upon the moist earth thereabouts. They 

 are best observed by disturbing moss and grasses, from which they then 

 come forth. They run about upon the mud or even upon the water, 

 though they do not take to the water as readily as do the Merragatas and 

 Microvelias. A few notes on the habits of these insects are given in 

 "Brauer, 1909"; in "Guide to British Water Bugs," by Kirkaldy, 1899; 

 in collecting notes by Bueno, and in Kulgatz's article "Die Aquatilen 

 Rhynchoten Westpreuss," 1911. 



Kulgatz says that Hebrus ruficeps lives in Sphagnum and has been 

 taken in January, May, June, July, August and September, October and 

 November. He found them under a 16-cm. snow layer, wintering as 



