INSECTA. 541 
First joint of tarsi equalling or surpassing the second in length. 
Antenne with nine or eight joints, the first elongate, the last three 
incrassated, forming a club. Body ovate or orbicular. 
Sub-genera : Cercyon Leacu (Cercyon and Trichopoda Bruty), 
Spheridium Far. (in part), Cyclonotum Dis. (Celostoma Bruuu¥). 
Sp. Spheridium scarabeoides Fasr., Dermestes scarabcoides L., Vout Coleopt. 
I, Tab. 32, fig. 1, Panzer Deutschl. Ins. Heft 6, Tab. 2, Sturm Deutschl. 
Faun., Ins, Tab, xx1. &c. These insects live on the land in dung. Other 
species live under wet moss, or in muddy ground. 
Hydrophilus Gnorrr., Fasr. Maxillary palps with second 
joint not incrassated. Maxille with two coriaceous lacinie. First 
joint of tarsi very short, connate with the second. Antenne with 
eight or nine joints. Body ovate. Thorax broader posteriorly. 
A. With antenne of nine joints. 
1. With sternum carinate. 
Hydrophilus Faxr. (in part), Zydrophilus and. Hydrobius Lracu. 
Sp. Hydrophilus piceus Fasr., Dytiscus piceus L., DuMERIL Cons. gén. s. l. 
Ins. Pl. 6, fig. 9, PANzER Deutschl. Ins. Heft 110, Tab. 12; the largest 
species of this genus 13 to 1# inches long, pitch-black, shining, the 
antennz and feelers red-brown ; the thorax terminating in a sharp point 
between the hind-feet. This beetle lives in fresh water, and feeds especially 
as perfect insect, yet also as larva, on water-slugs, and swims very quickly. 
The abdomen is covered beneath with a stratum of air, as though with 
silver. This air (a provision for respiration) is renewed by the beetle, by 
means of air-bubbles taken up on his antennz, which he brings from time 
to time to the surface of the water (NirzscH in RetL’s Archiv f. d. 
Physiol. X. p. 440). The female spins for her eggs an oblong, pod-shaped 
nest of a yellow-brown colour, terminating above in a little curved horn, 
which floats on the water amongst the duckweed. In this the eggs lie in 
regular order. The young larve, some time after they have come forth 
perforate this web, and cast themselves into the water. See LYonerr in his 
translation of Lesser, Théologie des Ins. I. p. 159, fig. XVI. and Ouvrage 
posthume, pp. 133—151, Pl. 13; compare also MicEr, Ann. du Mus. 
d’ Hist. nat. XIV. pp. 441—459, Pl. 28.—Hydrophilus scarabeoides Fasr., 
(Hydrobius) PANzER Deutschl. Ins. Heft 67, Tab. 12, &c. 
2. With sternum simple. 
Cyllidium Ericuson. 
B. With antenne of eight joints. 
Berosus, Laccobius, Limnebius LEacu. 
Helophorus Iuu1G. (Elophorus Fasr.). Maxillee with two cori- 
aceous laciniw. Maxillary palps with second joint not incrassated. 
