BIOLOGIA CENTRALI-AMERICANA. 
ZOOLOGIA. 
Class INSECTA. 
Order COLEOPTERA. 
Tribe ADEPHAGA (continued). 
Fam, HALIPLIDA. 
This family at present consists of about fifty species of aquatic carnivorous Coleoptera, 
and is probably as well represented in the northern and temperate as it is in the tropical 
regions. It is of wide distribution; but only one or two species are yet known from | 
South America, while, on the other hand, North America has furnished a considerable 
proportion of the forms at present extant in our collections. 
CNEMIDOTUS. 
Cnemidotus, Illiger, Mag. Ins. i. p. 8373 (1802). 
This is a small genus of about eight species, but has a wide extension in the northern 
hemisphere, from Europe to Japan and China on the one side, and to North America, 
east and west, on the other. 
1. Cnemidotus simplex. 
Cnemidotus simplex, Lec. Ann. Lyc. N. Y. v. p. 201". 
Hab. Norta America, San Diego!.—Muexico, Guanajuato (Dugés, coll. Sallé), Jalapa 
and Oaxaca ({Hoge). 
The Mexican individuals depart considerably from Californian specimens, being 
much narrower and with less coarse sculpture; the Guanajuato specimens, however, 
differ considerably from the large series found by Hoge, and approach more nearly to 
the Californian individuals; so that the superficial characters above mentioned, unac- 
companied as they are by any structural distinctions, do not warrant us in treating the 
Mexican individuals as a species distinct from that of California. 
BIOL. CENTR.-AMER., Coleopt., Vol. I. Pt. 2, Aprid 1882. BB 
