98 r October, 
portion roughly pimctured ; middle keel slight ; tubercles of the 
hinder angles small but distinct ; under-curved sides, below the 
hinder angles only, with a yellow, hindwardly widened streak. 
Elytra blue-black, apex fuscous, nerves with golden-yellow scale- 
hairs. Sternum, especially at the sides, with a silvery gloss, in the 
$ brassy, but in both sexes grey or blackish next the pronotum ; 
.prosternum yellow, black in the middle ; metastermim posteriorly, 
in the ^ , with a very small tubercle ; sheaths of all the coxse 
unkeeled, black, 2nd pair on the middle and at the inner side with 
a silvery streak. Legs — Coxce black above, yellow beneath ; fulcra 
yellow, 1st pair with a black central streak ; thighs, 1st pair black, 
yellow inwardly at the base, 2nd and 3rd pairs black-brown above, 
yellow-brown beneath ; tihice and tarsi all black. 
Abdomen — beneath with a silvery gloss, in the $ brassy at the sides ; 
in the ^ , on the 6th segment, in the middle, two short, stout, obtuse, 
forwardly directed, black, spinous processes ; posterior margin in 
the middle with a deep, rounded excision, on each side of which 
the colour is brown ; in the ? the posterior margin of the 6th 
segment is raised, brownish in the middle, and slightly and 
regularly excavate. Genital segments, in the ^ long- oii 'tbe 
upper-side the 1st long, quadrangular, projects much beyond the 
points of the connexiva, black, posterior angles brown ; 2nd very 
short, obtuse ; beneath, the 1st posteriorly almost squarely cut out, 
the middle projecting a little on to the 2nd, the sides receding 
gradually to a point ; the 2nd long, cylindrical, rounded behind, 
black, brown posteriorly, covered with a whitish gloss. In the $ 
beneath, short, the 1st yellowish, trapezoidal, tapering posteriorly, 
with a deep rounded furrow across the base ; 2nd very small. 
Length 3| — 3f lines. 
Most like H. lacustris, but easily distinguished by being always 
black beneath ; the ^ by the processes on the 6th abdominal segment ; 
the $ by the furrow on the 1st genital segment. 
Hitherto not common, or overlooked. Taken at Lee and Gravesend, 
on still water, in April and May. 
CETPTOCEEATA. 
Section 5. — Coeixina. 
Family 1. — Coeixid^. 
Qenus 1. — Coeixa, Geoffr. 
Species 9*. — Coeixa pe^tjsta. 
CoEiSA PEJ5U8TA, Fieh., Syn. Coris No. 14 (1848) ; Spec. Coris. 28, 30, 
