INSECTA. 541 



"irst joint of tarsi equalling or surpassing the second in length, 

 itennae with nine or eight joints, the first elongate, the last three 

 ssated, forming a club. Body ovate or orbicular. 



Sub-genera : Cercyon LEACH (Cercyon and Trichopoda BRULLE), 

 Sphceridium FABE. (in part), Cyclonotum DEJ. (Codostoma BRULLE). 



Sp. Sphceridium scarabceo'ides FABR., Dermestes scardbceoldes L., VOET Coleopt. 

 i, Tab. 32, fig. i, PANZER Deutschl. Ins. Heft 6, Tab. 2, STURM Deutschl. 

 faun., Ins. Tab. xxi. &c. These insects live on the land in dung. Other 

 species live under wet moss, or in muddy ground. 



Hydrophilus GEOFPR., FABR. Maxillary palps with second 

 joint not incrassated. Maxillge with two coriaceous laciniae. First 

 joint of tarsi very short, connate with the second. Antennae with 

 eight or nine joints. Body ovate. Thorax broader posteriorly. 



A. With antennce of nine joints. 



1. With sternum carinate. 



Hydrophilus FABR. (in part), Hydrophilus and Hydrobius LEACH. 



Sp. Hydrophilus piceus FABR., Dytiscus piceus L., DUMERIL Cons. gn. s. I. 

 Ins. PI. 6, fig. 9, PANZER Deutschl. Ins. Heft no, Tab. 12 ; the largest 

 species of this genus i| to if inches long, pitch-black, shining, the 

 antennae 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 antennae, which he brings from time 

 to time to the surface of the water (NiTZSCH in REIL'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 larvae, some time after they have come forth 

 perforate this web, and cast themselves into the water. See LYONET in his 

 translation of LESSER, Theologie des Ins. I. p. 159, fig. xvi. and Ouvrage 

 posthume, pp. 133 151, PI. 13 ; compare also MIGER, Ann. du Mus. 

 d'ffist. not. xiv. pp. 441 459, PL 28. Hydrophilus scarabceo'ides FABR., 

 (Hydroltius) PANZER Deutschl. Ins. Heft 67, Tab. 12, &c. 



2. With sternum simple. 

 Cyllidium ERICHSON. 



B. With antennce of eight joints. 

 Berosus, Laccobius, Limnebius LEACH. 



Helophorus ILLIG. (Elophwus FABR.). Maxillae with two cori- 

 aceous lacinige. Maxillary palps with second joint not incrassated. 



