the Land and Water Bugs. 229 



and, on examining it more closely, it will be found to have 

 moderately long 4-jointed antennae, slender legs, formed for 

 running, and a long rostrum. In the French genus Pelogonus, 

 for an authentic specimen of which I am indebted to the late 

 celebrated Latreille, the legs are slender, for running, and the 

 rostrum long, as in the preceding insect; its habits also are 

 similar, but the antennae are reduced to a very minute size, 

 and are almost hidden under the eyes. In both the foregoing 

 instances, the wing-cases entirely cover the abdomen. In the 

 very common British insect, Naucoris cimicoides, we find a 

 still greater departure from the previous characters. This 

 insect is found in the water, swimming about with rapidity, 

 by means of its fringed hind legs; and seizing its prey with its 

 fore legs, which are short, thick, and hooked; its antennae 

 are very minute, and concealed beneath the eyes ; its rostrum 

 short, thick, and bent, and the margins of the abdomen not 

 covered by the wing-covers. 



It will be perceived that the passage between the two great 

 groups is not clearly established by the preceding insects ; a 

 link being wanted which shall possess the slender legs, and 

 long rostrum of Acanthia and Pelogonus, with the swimming 

 habits, fringed hind legs, and exposed abdominal margins of 

 Naucoris. 



This link is found in the genus which I now propose, 

 under the name of Aphelocheirus*, with the following charac- 

 ters : — 



Corpus ovato-depressum ; antennae breves, sub oculis fere absconditae. Ro- 

 strum elongatum. Pedes omnes tenues, antici simplices, postici 4 ciliati 

 natatorii. Hemelytra abdominis margines non tegentia. 



Body ovate, depressed ; antennae short, nearly concealed beneath the eyes. 

 Rostrum long, formed as in Acanthia. All the legs slender, the fore 

 pair simple, not raptorial, the two hind pairs fringed, and formed for 

 swimming. Wing cases not covering the margins of the abdomen. 



The type of this genus is the Naucoris aestivalis of 

 Fabricius (figured by Coquebert, tab. x. f. 4.), which 1 have 

 much pleasure in announcing, for the first time, as an in- 

 habitant of our country, having captured a specimen in the 

 river Evenlode, near Ensham, Oxon : I have also received 

 specimens from the neighbourhood of Oxford ; and from Sut- 

 ton Park, in Warwickshire ; arid, through the liberality of the 

 administrators of the Jardin des Plantes, I likewise possess 

 one of the two original specimens, described by Fabricius, 

 from the collection of M. Bosc. 



J. O. Westwood. 

 The Grove, Hammersmith. April 10. 1833. 



* Derived from the Greek, in allusion to the simple fore legs. 

 Q 3 



