26 ADEPHAGA. 
to converge, and are continued forwards as two acute elevations along the middle of the 
metasternum ; these two lines are approximate and parallel in the anterior part of their 
course, and terminate in front at the edges of the metasternal groove receiving the 
prosternal process. The two species of the group are, in addition to the H. adumbratus, 
the North- and South-American Hydroporus pulicarius, Aubé, and the Cuban H. caraibus, 
Chev. All these three species are excessively similar to one another; and their limits 
are doubtful; it is indeed by no means clear that the Paso-Antonio specimens are 
certainly of the same species as the Mexican individuals described by Clark. I am not 
quite sure about the structure of the front feet; but if, as I believe, the two anterior 
pairs are 5-jointed, it is probable these insects form a genus allied to the peculiar 
Australian Sternopriscus, to which they are a good deal similar in appearance. 
CQELAMBUS. 
Colambus, Th. Sk. Col. u. p. 18; Sharp, Trans. Roy. Dubl. Soc. n. s. 1. p. 861 (1882). 
About fifty species are united to form this genus. ‘They are characteristic more 
especially of the North-American and Mediterranean regions, none being known from 
the Antilles or South America. 
1. Celambus wardi. 
Hydroporus wardii, Clk. Ann. & Mag. Nat. Hist. ser. 3, x. p. 177; Sharp, Trans. Roy. Dubl. 
Soc. n. s. i. p. 399. 
Hab. Mexico, Guanajuato (Dugés, coll. Sallé), Puebla, Parada, Toluca (Sal/é), 
Oaxaca (fége). 
2. Celambus medialis. 
Hydroporus medialis, Lec. Ann. Lyc. N. York, v. p. 209; Sharp, Trans. Roy. Dubl. Soc. n. s. ii. 
p. 401. 
Hab. Nortu America, San Diejo, California—MeExico, Jalapa and Oaxaca (Hége). 
3. Coelambus infacetus. 
Hydroporus infacetus, Clk. Ann. & Mag. Nat. Hist. ser. 3, x. p. 180°; Trans. Roy. Dubl. Soe. 
n.s. i. p. 798. 
Hab. Mexico (Truqui'). 
The unique type of this species is unfortunately lost. It will not be easy from the 
description to determine the species with certainty; but it would appear that it is 
probably an insect allied to Hydroporus medialis, Lec. 
DERONECTES. 
Deronectes, Sharp, Trans. Roy. Dubl. Soc. n. s. ii. p. 865. 
Hydroporus (ex parte), Aubé, Spec. Gén. vi. p. 468. 
