Aquatic Hemiptera. 
79 
Intermediate femora and tibiae subequal, each equal in length to the 3 apical 
joints of the antennae together. Posterior femora incrassate, shorter than inter- 
mediate femora ; fore tarsi single jointed, intermediate and posterior two-jointed. 
Length 2 mm. ; breadth between posterior pronotal angles 075 mm. 
9 {immature). Head similar in shape to that of the male, dull fuscous ; two 
light brown patches on front; a central, black, shining, longitudinal carinate line ex- 
tending along the entire length of the head; upper surface covered with fine erect 
hairs which are most dense and silvery at the inner margins of the eyes and at the 
base of the head ; on each side of the medial carina are two very minute black tubercles 
placed obliquely in front of each eye. These are not visible in the male specimen. 
Antennae as in male. Underside of head stramineous ; rostrum as in male^ but a little 
shorter, scarcely passing the anterior coxae. 
Pronotum hairy, dark fuscous brown with three light brown spots on the ante- 
rior area, broader than long, the anterior margin broadly concave, the posterior 
margin convex, lateral margins oblique. Mesonotum broader than pronotum, deep- 
ly centrally impressed by an oblique line ; a patch of silvery hairs at each later- 
al angle ; a somewhat large quadrate patch on the disk of the mesonotum, light 
brown ; anterior lateral margins obliquely ascending. Metanotum very narrow, 
lateral margins oblique; a patch of silvery hairs at each outer angle; entirely dark 
brown. 
Sternum entirely pale stramineous, slightly hairy, a thin black line between the 
pro- and mesopleura ; a slightly thicker black line between the me.so- and metapleura ; 
this line is continuous with a black band made up of somewhat large black sub- 
triangular lateral patches at the bases of the ventral abdominal segments and the 
stigmatal spots. 
Legs very much the same as those of the male. Apices of the distal tarsal 
joints black or fuscous. All the tarsi one-jointed. 
Abdomen above dark brown, outer margins of segments almost dull black ; very 
hairy with patches of silvery hairs which are visible in certain lights ; connexivum 
yellowish brown, extending obliquely outwards. 
Underside of abdomen and connexivum pale yellowish, hairy. 
Length. — 2 mm. ; breadth between posterior pronotal angles, i mm. 
Subfamily GERRINAE. 
Halobates sexualis, Distant. 
1903. Halohates sexualis. Distant, W. L., Fascic. Malay. Zool. I, p. 258, pi. XV, figs. 10, loa, 
lob ( <S and $ ). 
Three male specimens (one pinned and two in alcohol) from near Pak Payun, 
Tale Sap, i8-i-i6. 
In Distant' s figure the length of the head appears to be less than the distance 
between the inner margins of the eyes while in the Siamese specimens the head is 
longer than broad and is about twice as long as the pronotum. 
