INSECTA. 539 



Palps large, exsert. Elytra truncated. Tarsi short, with first joint 

 minute. Body oblong, depressed. Abdomen broader than thorax. 



Small coleoptera, with almost the habit of Hispa or Alurnus, exotic, often 

 met with, as it seems, in ants' nests. LINNAEUS first founded the genus in 

 A. DAHL Bigis Insectorum 1775, Amoenit. Academ. vm. p. 307. Compare 

 AFZELIUS Transact, of the Linn. Soc. Vol. iv. p. 243, &c. and WEST- 

 WOOD ibid. Vol. xvi. pp. 607684, PI. 33, and his Arcan. Entom. n. 

 pp. i 12, 3740, 7380, 261190. 



A. Head supplied posteriorly with a neck. 



Cerapterus SWED. Antennae with ten joints, club with nine 

 joints. 



Compare N. S. SWEDEKUS in VetensJc. ATcad. nya Handb. 1788, p. 203. 



Pentaplatarthrus WESTW. Antennae with seven or six joints, 

 club elongate, broad, with five joints. 



Paussus L. Antennae with two or three joints, club broad, exar- 

 ticulate. 



Sp. Paussus microcepTialus L., Amoen. Acad. vnr. Tab. vi. figs. 6 10 ; 

 Paussus tkoracicus DONOV., Pauss. trigonicornis LATK., Gen. crust, et 

 Ins. i. Tab. xi. fig. 8, &c. 



B. Head immersed in thorax. 



Ilylotorus DALM. Antennae with two or three joints, club 

 exarticulate, lanceolate, incurved, acuminate. Head furnished with 

 two conical tubercles (ocelli ?). 



Sp. Hylotor. Bucephalus GYLLENH. in SCHOENH. Syn. Ins. i. 3, App. Tab. vi. 

 fig. 2. 



Heterocerus Bosc. Antennae inserted under the lateral margin 

 of frons, with eleven joints, first two large, broad, two following 

 small, rest transverse, dilated, forming an elongated club. Head 

 received within thorax almost to the eyes. Mandibles porrect, den- 

 ticulate. Palps filiform. Body oblong, depressed, pubescent. 

 Tibiae, especially anterior, spinose. Tarsi quadriarticulate. 



Sp. ffeterocerus marginatus FABR., DUM^RIL Cons. gen. s. 1. Ins. PI. 7, fig. 7, 

 PANZER Deutschl. Ins. Heft 23, Tab. 12, &c. Small insects, the largest 

 species of which is scarcely more than 2'" long, and which in all their states 

 live in passages near the edge of the water. On the internal structure 

 compare LEON DUFOUR Ann. des Sc. natur. 2e Se"rie I. Zoolog. p. 60 and 

 following, with figures. 



