HYDROMETRA. 125 
between the anterior and intermediate coxe; the abdomen is very elongate; the 
antenne in the male are about two-thirds the length of the body, with joint 3 three 
times as long as 2, and 4 one-third longer than 3; the elytra in the winged female 
nearly reach the apex of the fourth dorsal segment. The male measures 133 (head 4, 
abdomen 51), the female 16 (head 44, abdomen 64) millimetres in length ; Guérin’s 
single specimen was considerably more elongate. H. metator, Buch. White, from the 
Amazons, must be a very closely allied form; it (¢ ) is described as having the antenne 
as long as the body. 
2. Hydrometra lentipes, n. sp. 
Black or pitchy-black, with a bluish-grey pruinosity, the base of the head and of the first joint of the antenne 
rufescent ; the legs brownish, the coxe and trochanters paler; the connexivum sometimes with a fulvous 
stripe ; the elytra pale brown, with blackish-brown nervures; the pronotum with a greyish-white median 
line; the under surface (in fresh specimens) clothed with greyish-white pubescence. Head considerably 
thickened at the base, as well as at the apex, appearing very narrow before and behind the eyes, the 
ante-ocular portion about twice as long as the post-ocular portion ; rostrum not reaching beyond the eyes ; 
antenne two-thirds the length of the body, joint 2 about twice as long as 1,3 nearly three times as 
long as 2, 4 nearly twice as long as 3. Pronotum with a few scattered punctures and a depressed 
median line. 
Length 93-1014, of the head 3-33, of the abdomen 4—4,), millim. (¢ 2.) 
Hab. Guatemata, Rio Naranjo and Paraiso (Champion). 
An apterous pair and a winged male, all from the low country bordering the Pacific 
Ocean. Very lke the insect here referred to H. caraiba, but less elongate and 
considerably smaller ; the head narrower, more dilated in front, more thickened at the 
base, with the ante-ocular portion relatively shorter; the abdomen less elongate. 
H. lentipes is also very like the Palzearctic H. stagnorum (Linn.), but it has a differently 
shaped head, a shorter rostrum, and longer antenne. ‘The head is thickened at the 
base in all three examples. /. lineata, Say, is probably a nearly allied form, but 
specimens of it are not available for comparison. 
3. Hydrometra mensor. 
Hydrometra mensor, Buch. White, Trans. Ent. Soc. Lond. 1879, p. 267 (3) *. 
Apterous form. 2. Brownish-testaceous, the apices of the tibia and of the two basal joints of the antenna, 
the tarsi, the eyes, and the inner and outer raised connexival margins blackish-brown, the pronotum with 
indications of a paler median line. Head scarcely thickened at the base, with the ante-ocular portion 
about twice as long as the post-ocsular portion ; rostrum nearly reaching the base of the head; antenne 
comparatively short, about one-third the length of the body, jot 2 twice as long as 1, 3 twice as long 
as 2, 4 much longer than 2. Metanotum much shorter than the pronotum. 
Length 114, of the head 3, of the abdomen 5? millim. 
Hab. Panama, David (Champion).—Amazons, Manaos ', Santarem. 
One specimen, nearly agreeing with a winged female from Santarem in the British 
Museum. Buchanan White did not mention the form of the antenne. The two sub- 
elongate elevations near the posterior margin of the pronotum (visible in the Santarem 
