FAMILY HVDROMETRID^:. 167 



Genus GALGULUS. 



Body short, dilated ; antennae short, terminated with a round knob, and placed in a cavity 

 beneath the eyes ; eyes subpedicellate ; mouth promuscidate ; head triangular ; arm 

 or humerus dilated ; tarsi single-jointed, armed with two claws : on the hindlegs, the 

 tarsi are two-jointed, and armed with a double claw. 



Galgulus oculatus. 

 Color brown or dark brown : head vertical, appears truncated before ; eyes somewhat 

 kidney-form, elevated, with their front and sides formed for vision. Head and thorax 

 rough or warty ; posterior edge of the thorax thickened, and edge luteous, emarginate. 

 Scutellum large, traversed by a ridge, and impressed with a line upon its middle ; 

 sides tuberculated : the whole appears rough. Wing-covers rough, with two or three 

 rows of small tubercles running parallel with the sides. Forelegs placed in front, 

 raptorial, and with a large dilated humerus : thighs of the middle legs somewhat 

 dilated ; hindlegs long and slender, the two last pair are banded. Length rather less 

 than a quarter of an inch. 

 Resembles a small toad, and inhabits muddy places, where it may be seen running, and 

 sometimes leaping. I have found it in great numbers in the latter part of May, running 

 and hopping upon the mud beside streams of water. * 



Hydrometridae. 



The habits of the Hydrometridje are peculiar. Though they have wings, they scarcely 

 ever use them. They do not live in water, nor upon the land. In the spring, summer and 

 autumn, almost every running stream, and pool connected with it, will furnish many 

 individuals of this family, which, from their mode of progression over the surface of the 

 water, have been called skippers. Their legs are long and angulated, and their bodies are 

 raised considerably above the surface over which they glide. The antenna? are long and 

 slender, and the surface of their bodies is protected from the wetting action of water as 

 perfectly as if varnished : a skipper, immersed in water, comes out as dry as if it had 

 been protected by an india-rubber coat. The surface of the insect, examined under the 

 simple lens, is bright and glossy or lustrous, from the presence of a close nap, which is 

 doubtless the means whereby the water is repelled. 



The antennae are four-jointed ; the first longest, and in the Gerris they are placed 

 directly before the eyes. The forelegs are very much advanced, and seem to belong to the 

 head, but are still attached to the breast ; the tarsi are two-jointed. 



The appearance of the Gerris is not very much unlike that of Reduvius, and the forelegs 

 might be used for grasping. Gerris marginatus is the most common speeies. Dr. Harris 



