COLEOPTERA. 469 



by their narrow and elon,G;ated form, their thorax Avhich has the 

 figure of a long square, and the prominence of their eyes *. 



Sometimes tlie maxillary jjalpi are subulate or terminate in a more 

 slender joint, short and conical. 



OcTHEBius, Leac/s, Germ. — Elophorus, Fab. — Hydr.exa, IlHg., Lett. 



The thorax is nearly semi-orbicular f . 



There, the maxillary palpi, terminated by a fusiform joint, larger 

 than the penultimate and pointed at the end, arc much longer than 

 the antennae and head. The epistoma is strongly emarginated. 

 Their appearance otherwise is that of the Octhebii, 



Hydr^na, Kugel. Leach X. 



In the other Hydrophili the body is ovoid or almost hemispherical, 

 and generally convex or arched, and the thorax always smooth and 

 wider than it is long ; the tibiae are terminated by strong spurs, and 

 the tarsi most frequently ciliated. The extremity of their mandibles 

 isbidentated. They embrace the family of the Hydrophilidea, Leach, 

 or the genus Hydrophilus, Fab. 



Some have but six joints in the antennae ; their epistoma is emar- 

 ginated. Such are those which form the 



Spercheus, Fab. §. 



In the following the antennfe are always composed of eight or nine 

 joints, and the epistoma is entire, or on the anterior margin slightly 

 concave. 



A species transmitted to us by our friend Doctor Leach presents 

 such singular characters that we have been induced to consider the 

 Insect as the type of a new subgenus ||, the 



Globaria, Lat. 



So named because its body is almost spherical and laterally com- 

 pressed, and because it appears susceptible of forming a ball, like an 

 Agathidium, Its antennae appear to me to be composed of but eight 

 joints, of which the fifth is dilated into a spine at the internal side, 

 the sixth forms a reversed and elongated cone, the seventh cylindri- 



* Elophorus dongafus, Fab. ; — E. crenaftis, Id. ; — brevis, Gyllenh. See Germ., 

 Insect. Spec. Nov. I, p. 90. 



f E. ptjgmceus, Fab. ; —Hydrana riparia, Lat. ; — Hydrcena margipallcns , Lat. ; 

 — Elophorus marinns, Gyll. See Germ., lb., p. 90. 



X E. mininms. Fab. Gyll.; Hi/praiia riparia, Kugel. ; H. longipalpis, Schoenh., 

 Germ., Faun. Insect., Eur. VIII, 6. For the other species, see Germ., Insect. 

 Spec. Nov., I, p. 93. 



§ Spercheus emarginafus, Fab. ; Panz., Faun. Insect. Germ., XCI, 4. M. Bour- 

 don, a French naturalist who is now exploring Colombia, first discovered this 

 species in the vicinity of Paris. 



II It would seem to come more naturally near that of Berosus, Leach; but on 

 account of the number of the antennal segments, I think it best to place it directly 

 after Spercheus. This order, however, might be reversed by commencing with 

 those subgenera which have nine joints in the antennae, and ending with those iu 

 which there are three legs, or with Globaria and Spercheus. 



