EEPORT ON THE PELAGIC HEMIPTERA. 69 



Middle and hind legs long and slender, inserted at the sides of the posterior end 

 of the thorax, the hind legs inserted above the middle legs. Middle legs 

 without a fringe of long hairs. Tarsus two-jointed, second joint clawed 

 before the tip. Hind legs with two-jointed tarsus, the second joint clawed 

 before the tip. 



Abdomen short ; sides furnished with a conspicuous connexivum. Apex of the 

 abdomen in the male without a conspicuous rhomboidal appendage. 



Type of genus : Halobates lituratus, St§,l. 



In general form resembling Halohates, but with a different facies, and easily distin- 

 guished by the shape and structure of the head and front tibia, the two-jointed hind 

 tarsus, differently constructed abdomen and genital segments, and much less pubescent 

 integuments, as well as by the more variegated coloration. 



DETAILS OF STEUCTUllE. 

 The Head and its Appendages. 



The Head (with the eyes) presents, when viewed from above, a somewhat semicircular 

 outline. Without the eyes it is oblong, the front and hind margins slightly rounded, and 

 the sides slightly concave. The vertex is more or less convex ; the face perpendicular ; 

 the middle lobe larger than the side lobes, widest at the apex, which is truncate ; and the 

 side lobes triangular. The Ei/es, viewed from above, are subtriangular in outline, with 

 the outer margin rounded ; the inner margin nearly straight ; and the hind margin 

 concave, resting on the sides of the pronotum. Seen from below, the eye is subtriangular 

 in outline. There are no ocelli nor ocellus-like spots. 



The Antennce (PI. H. figs. 4 «., 5 a., 6 «.) are four-jointed, the first joint being 

 the longest, slightly curved, and usually thinnest in the middle. The second joint is 

 slightly incrassate upwards, and between the second and third joints is a distinct jointlet. 

 Between the third and fourth is also a minute jointlet. The fourth joint is usually 

 fusiform. The antenniferous tubercles are situated between and close to the eyes and side 

 lobes of the face, and form cups to receive the antennae, the inner side of the rim being 

 incised as in Halohates. 



The Rostrum reaches to the front margin of the mesosternum, and is four-jointed. 

 The first joint is stout, and about as broad as long. The second is ring-like ; the 

 third is the longest ; and the fourth is shorter than the third, and thinner. 



