562 On Aquatic Carnivorous Coleoptera or Dytiscide 
The seven genera may be readily distinguished as follows :— 
[ Coxal incision distinct ; upper sur- \ AGYIMBUS. 
| @onnlaslines face with sculpture. American. (Vide p. 596.) 
ouliseraise, Coxal incision wanting ; upper sur- | LACCONECTUS. 
face without sculpture. Asiatic. | (Vide p. 598.) 
( Upper surface with sculpture ; 
thorax without lateral margin ; 
| AGABETES 
Coxal pone prosternum not sulcate. 
| 
| 
(Vide p. 599.) 
eee 
very broad. 
Prosternum longitudinally sulcate MATUS. 
along the middle. (Vide p. 599.) 
Coxal lines 
present. 
I 
COPELATUS. 
( Vide below.) 
Goraleihorder along the middle. 
very narrow. 
Coxal lines normally distant ; pro- 
sternum much incrassate along the 
middle. 
COPTOTOMUS. 
(Vide p. 601.) 
deflexed outside the coxa as a linear band. 
Front of hind coxa very arched, so that the wing 
of the metasternum is very slender, and 
L 
[ WO One 
| prosternum but little incrassate 
L 
' 
L 
T’ront border of hind coxa but little arched, wing of metasternum rather 
large, not linear, not deflexed outside coxa. 
L 
LANCETES. 
Coxal lines very close to one another; \ 
) 
[ 
J 
} ( Vide p. 602.) 
I. 54.—Genus COPELATUS. 
Coxal lines extremely close to one another, especially in their hinder portions, 
where just before their abrupt divergence to form the borders of the coxal processes 
they are very nearly contiguous with the central line forming the suture of the two 
coxee ; at the anterior part of the coxal processes they become excessively fine so 
that they can with difficulty be perceived, and are abruptly diverted outwards at 
right angles to their former course. 
The species are numerous* and are found in nearly all the warmer parts of the 
world; the sculpture of the elytra which frequently consists of elongate strice offers 
a, ready method of arranging them in fourteen groups; seven of these groups 
possess in addition to the conspicuous regular stric, a short additional stria placed 
*Tn addition to those enumerated in the succeeding text, it is probable that the following should be 
referred to the genus. Colymbetes bimaculatus, Perroud (No. 1216)? group I; New Caledonia.—Copelatus 
angustatus, Chev. (No. 1258) near No. 882; Cuba.—Copelatus australiw, Clark, (No. 1259) near No. 
815; Australia —Copelatus basalis, Boh. (No. 1260); Caffraria.—Copelatus elongatulus, Macl. (No. 
1261) near No. 808; Australia.—Copelatus externus, Kirsch, No. 1262); Peru.—Copelatus formosus, 
Woll. (No. 1263); Africa aid Cape Verde Islands.—Copelatus gallapagoensis, Wat. (No. 1264) near 
No. 875 ; Galapagos Islands.—Copelatus normalis, Er. (No. 1265) ; Peru.—Copelatus obtusus, Boh. (No. 
1266) ; Caffraria.. —Copelatus quadrisignatns, Regt. (No. 1167); Manilla.—Copelatus stvriatellus, Boh. 
(No. 1208) ? Caffraria.—Coypelatus striaticollis, Lue. (No. 1260) ; South America.—Copelatus substriatus, 
Kirsch, (No. 1270) ; Peru.—Copelatus undecimstriatus, Aubé, (No. 1271); Cayenne.—Dytiscus bicolor, 
Fab. (No. 1286); Africa. 
