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Show 394 INSECTA. Ei.oPaon.us, Fab.-Silpha, L.-JJermestes, Geoff.-Hydrophilm, De . Geer. The body oval, and the thorax transver~al; the eyes but slightly prominent( 1 ). liYDnooaus, Germ.-Elophorus, Fab. Th~ Hydrochi are only distinguished from the preceding subgenus by their nart·ow and elongated form, their thorax, which has the figure. of a long square, and the prominence of their eyes(2). Sometimes the maxillary pal pi are subulate or terminate in a more slender joint, short and conical. OoTHEnrus, Leach, Germ.-Elophorus, Fab.-llydrrena, Illig., Lat. The thorax is nearly semi-orbicular(3). There, the maxillary palpi, terminated by a fusiform joint, larger than the penultimate and pointed at the end, are much longer than the antennre and head. The epistoma is strongly emarginated. Their appearance otherwise is that of the Octhebii. H YDRJENA, Kugel. Leach( 4). In the other H ydrophili the body is ovoid or almost hemispherical and generally convex or arched, and the thorax always smooth and wider than it is long; the tibire are terminated by stt·ong spurs, and the tarsi most frequently ciliated. The extremity of their mandibles is bidentated. They embrace the family of the Hydrophilidea,Leach, or the genus Hydrophilus, Fab. Some have but six joints in the antennre; their epistoma is emar· ginated. Such are those which form the SPEnoaEus, Fab.(s) I~ the following the antennre are always composed of eight or nine ( 1) The Elophori of :Fabricius, those species excepted which belong to the following subgenera. (2) Eloplzorus elongat~a, Fab. ;-E. crenatua, Id. ;-E. brevia, , Gyllenh. See Germ., Insect. Spec. Nov., I, p. 90. (3) E. pygmreua, Fab. ;-Hydrrena riparia, Lat. ;-Hydrrena margipal/eru, Lat.; Eloplwrua marinua, Gyll.; see Germ., lb., p. 90. (4) E. minimua, Fab. Gyll.; Hydr;mw riparia, Kugel.; II. longipalpia, Schrenh., Germ., Faun. Insect., Eur. VIII, 6. I~or the 9ther species, see Germ., Insect. Spec. Nov., I, p. 93. (5) Spercheus emarginatua, ~'ab.; Panz., :Faun. Insect. Germ., XCI, 4. M. COL~OPTEUA. 395 joints, and .the epistoma is entire, or on the anterior mar.gin 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( 1) the GLoBARIA, Lat. So named because its body is almost spherical and laterally compressed, and because it appears susceptible of forming a bal1, like an Agathidium. Its antennre 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 cylindrical, and the last or the eighth conical; these latter joints form an almo3t cylindrical and greatly elongated club, which terminates in a point. The maxillary pal pi are a little shorter than the antennre. The eyes are la1·ge and prominent. The thorax is almost semilunar. The elytra completely clasp the abdomen. The pectus is destitute of a sternal spine. The extremity of the four posterior tibire is furnished with a bundle of setre almost as long as the tarsus. The scutellum is sma11, triangular, elongated, and narrow. The only species known, G. Leachii, is smaiJ, and foreign to Europe. I believe it is from South America. All the remaining Hydrophilii have nine joints in their antennre; the club is oval or ovoid. The body is not susceptible of being contracted into a ball. In the largest species, the two intermediate joints of the ~ntennal club, or the seventh and eighth, are reniform or irregularly lunate, ob~use at one end, prolonged, arcuated, and pointed at the · other, with a remarkable space between them; the first of this club is cupulate and most prolonged anteriorly. The middle of the sternum is elevated into a carina, and terminated posteriorly in a point more or less long, and very acute. The maxillary palpi are longer than the antennre; their last joint is shorter than ~he penultimate. The tarsi, particularly the last, are compressed, fringed with hairs or cilia along their internal side, and terminated by two hooks, ge- Bourdon, a French naturalist who is now exploring Colombia, first discovered this species in the vicinity of Paris. ' (l) It would seem to come more naturally near that of D:tnosus, Leach; but on account of the number of the antenna! 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 antenna:, and ending with those in which there are three less, or with Globnria and Spcrchcus. |