468 
inskcta. 
four very distinct joints, or of five, the first of which is much shorter 
than the second ; all the joints are entire. 
Those in which the legs are natatory, the first joint of the tarsi is 
much shorter than the following ones, and the maxillae are entirely 
corneous, will form our first tribe, that of the Hydrophilii, which 
embraces the genus 
Hydrophilus, Geoff. 
Linnaeus mei’ely made these Insects a division (the first) of his genus 
Dytiscus, but their anatomy is essentially different. The alimentary 
canal of the Hydro phili is very analogous in its contexture and 
length, which is more than four or five times that of the body, to 
that of the Lamellicornes, and only approximates to the same canal 
of the carnivorous Insects with respect to the biliary vessels. They 
neither have the natatory bladder nor excrementitious apparatus which 
characterize the Hydrocanthari. In the females only, this appara- 
tus is replaced by organs which secrete the matter that is to form 
the cocoon that encloses the ova, and to produce it their anus is fur- 
nished Avith two fusi. Finally, the male organs of generation have 
the closest aflfinity with those of the Clavicornes *. 
In some, where the body is oval, oblong and depressed, or elon- 
gated and narroAV, the thorax scabrous and narrowed posteriorly, the 
tibiae are slender and furnished with small spurs, and the tarsi fili- 
form, slightly ciliated and terminated by tAVO strong hooks ; the an- 
tennae — ahvays composed of nine joints — terminated in a slightly 
perfoliaceous or nearly solid club, almost in the form of a reversed 
cone, and the extremity of the mandibles is entire, or ends in a sin- 
gle tooth. They are all very small, sAAum but seldom or badly, and 
inhabit stagnant Avaters, from Avhich they occasionally remove, to 
conceal themselves under stones or in the earth. They compose the 
family of the Helphoridea of Leach, a name Avhich reminds us of the 
genus Elophorus of Fabricius. 
Here the length of the maxillary palpi does not surpass that of the 
antennae or is even less. The epistoma is entire or Avithout any nota- 
ble emargination. 
Sometimes the maxillary palpi are terminated by a thicker and 
oval joint. 
Elophorus, Fah. — Silpha, L. — Dermestes, Geoff. — Hydrophilus, 
De Geer, 
The body oval, and the thorax transversal ; the eyes but slightly 
prominent f . 
Hydrochus, Germ. — Elophorus, Fab. 
The Hydrochi are only distinguished from the preceding subgenus 
* “The conformation and structure of the male organs of generation in the Pal- 
picornes fully justify the position in the entomological series, assigned to them by 
M. Latreille.” — LeonDufour, Ann. des Sc. Nat., VI, p. 172. 
-f- The Elophori of Fabricius, those species excepted which belong to the following 
subgenera. 
