714 On Aquatic Carnworous Coleoptera or Dytiscide. 
The front tarsi of the male are rather small for the size of the insect, being about 
32 m.m. in the transverse direction; beneath the palettes are narrow, the 
pubescent area large, and the basal fringing hairs fine and but little developed. On 
the middle tarsi the basal joint bears beneath a very large patch of elongate, dense 
sexual hairs, they cover the whole of the joint and greatly overlap the following 
one. 
I have seen only a single individual of this species. It is the giant of the 
Dytiscide, much exceeding in bulk the largest individuals of Cybister giganteus. 
It is closely allied to that species but is distinguished by its larger size, and the 
male is also conspicuous by the great development of the sexual pubescence on the 
basal joint of the intermediate foot. The swimming legs are very powerful, their 
femora measuring 53 m1.m. across. 
Brazil, (coll. Saunders). 1114. 
I. 79.—Genus CY BISTER. 
Coxal lines present ; unguicular cleft narrow and angular at base ; only a single 
claw on the hind tarsus in the male sex; (the females also have only a single claw 
but in some cases a very rudimentary second claw exists). 
The numerous species* are widely distributed, but do not occur in South 
America. They may be arranged in six groups as follows :— 
fal (es pe #  ( Elytra with yellow lateral stripe ; male with axillar Group 1. 
Ses 5 =i ) | rug. (North American species.) Nos. 1119 to 1121. 
Oo oo <) 
ong Ca somes! 
ee a8 eee y | Hlytra without yellow lateral stripe; male Saas Group 2. 
- oe axillar ruge. (Asiatic and African species.) Nos. 1122 to 1134. 
Ard 
Bo Log 
A ag & ( ‘ug &. : : Group 3. 
2 eZ Bes Elytra without yellow lateral stripe, . : 6 4 Nos. 1135 to 1139. 
So 5 ay 
oF 3 Pas ! Elytra with yellow lateral stripe extending to and Group 4, 
a 8 A | 2 including the epipleura. Nos. 1140 to 1151. 
Ben, 2E 
© aS as 8 3 | Hlytra with yellow lateral stripe, which does not Group 5 
a =~ ° 2 | extend to or include the epipleura. Nos. 1152 to 1168. 
The female as well as the male furnished with swimming hairs on each side le eae 6. 
of the hind tarsi. es . 1169 to 1171. 
* The descriptions cited in the following list refer probably in part to species unknown to me:— 
Cybister auritus, Gerst. (No. 1275, huj. op.)?=No. 1280 ; Africa.—Cybister dejeani, Aubé (No. 1276); 
India.—Cybister jordanis, Reiche, (No. 1279)? No. 1169 var. ; Syria.—Cybister marginicollis, Boh. 
(No. 1280), near No. 1129; Caffraria.—Cybister olivieri, Crotch. (No. 1281); North America.— 
Cybister vulneratus, Klug. (No. 1283)? No. 1133 var. ; Arabia,—Dytiscus extenuans, Walk. (No. 1289) ; 
Ceylon.—Dytiscus tataricus, Gebl. (No. 1295)?=No. 1169; Tartary.—Trochalus rugulosus, Redt. 
(No. 1509)? near No. 1167 ; India.—Trogus natalensis, Wehncke (No. 1510)? near No. 1148 ; Natal. 
—The systematic position of the following is not quite clear :—Cybister prosterno-viridis, Orm. (No, 
1282) ;? South America, 
