123 
and Dytisci Complicali (p. 964), according to whether the metathoracie 
episternum reaches the intermediate coxal cavity or not. These are 
further sub-divided into the tribes Noterides (p. 260,944), Hydroporides 
(p. 319,950), Colymbetides (p. 490,956), and Hydaticides (p, 647,959), 
but the details of this arrangement cannot be followed here. 
As already noticed in the * * * § Catalogue of the Carabidte,’ Dr. Horn raises 
the Haliplini, Amphizoa, and Hydrachna* ( Pelobius ), to the rank of families. 
There is a strong consensus of opinion that to elevate these aberraut genera 
to the position of families and thus place them on a level with a family 
like the Carabidce is a step to be regretted as likely to lead to the un- 
necessary splitting up of other families on equally good grounds. The 
proper place for these groups appears to be as sub-families of the aquatic 
carnivora, uniting the Dytiscidce proper with the terrestrial carnivora. 
For convenience the name Dytiscidce may be applied to the whole group. 
Lacordaire t writes of the Haliplini that ces insectes n’appartiennent 
r^ellement pas non plus ii la famille ( Dytiscidce ) par leurs pattes j les 
tarses posteiieurs surtout resemblent completement a ceux d’une foule des 
Carabiques, leurs articles 6tant grilles, allonges et chaoun un peu renfl6 it 
leur extremity.’ lie adds that the characters given should place them at 
the head of the Dytiscidce which they connect with the Carabidce. Dr. 
Sharp X in his paper on the classification of the Dytiscidce, removed the 
Haliplini from that family and left it to ‘ the Carabophiles to decide 
whether they should be considered Carabidce or form a distinct family.’ 
Subsequently, however, ho makes them a separate family §. 
Lacordaire makes the genus Amphizoa also a tribe or sub-family, 
• qui presents un singulier melange des carac tires des Dytiscides et des 
Carabiques. Par ses organes bucoaux, sa t§te, ses antennes, et la non- 
contiguit6 des parapleures meta-thoraciques avec la base de l’abdomen, 
il appartient aux premiers, tandisque par ses pattes completement ambula- 
toires, son prosternum regu dan un sillon du mesosternum comme chez 
les Carabides, et la separation de ses saillies coxales, il rentre dans les 
seconds.’ It thus diminishes the differences between the aquatio and the 
terrestrial Carnivora. Leconte originally placed this singular genus in 
a distinct family and Chaudoir makes it a distinct group near to Trachy- 
* I do not understand the grounds on which the name Hydrachna for this genus 
(1801) has been sunk in favour of 1'aclohius [Pelobius) Schijnherr (1806), the species 
•tarda Herbst,’ the type given by Fabricius, being still considered as belonging to 
the genus. 
t Gen. Col. i p. 410. 
t O. B. Soc. Ent Belg., xxiii, 1880, p. cxlvii ; Dytisc., p, 97 4- 
§ Biol. Centr, Amor., Col, i (2), 1882, p. 1, 
