COLEOPTERA. 515 



THE FOURTH FAMILY OF THE COLEOPTERA PENTAMERA,— 

 The Clavicornes, — 

 Has, like the preceding family, four palpi ; the elytra entirely cover the upper side of the abdomen, or 

 its greater portion ; the antenna; almost always thicker at the tips, and often terminated by a perfo- 

 liated or solid mass. They are larger than the maxillary palpi, with the base naked or but scarcely 

 covered ; the legs are not fitted for swimming, and the joints of the tarsi, or at least those of the 

 posterior feet, are ordinarily entire. They feed for the most part in the larva state on animal matter. 



We divide this family into two sections, the first of which has the following characters : — Antenna; 

 always composed of eleven joints ; longer than the head, but forming after the third joint a fusiform 

 or cylindrical mass ; the second joint not dilated into an ear-shaped appendage ; terminal joint of the 

 tarsi, as well as the ungues, small, or of moderate size. 



These Clavicornes live out of water, whilst those of the second section are aquatic or subaquatic, 

 and thus lead to the Palpicornes, which are for the most part aquatic, and of which the antenna; have 

 not more than nine joints. The first section comprises several small tribes. 



The first tribe, that of the Palpatores, appears to approach, in a natural series, the Pselaphi and 



Brachelytra, [in respect of their mouth-organs and habits]. Their antennae (at least as long as the 



head and thorax) are slightly thickened to the tips, or are nearly filiform, with the two basal joints 



longer than the following ; the head is separated from the thorax by a narrowed part ; the maxillary 



palpi are long, advanced, and thickened at the tips ; the abdomen is large, oval, or ovoid, and laterally 



embraced by the elytra ; the legs are long, with the thighs clavate, and the tarsal joints entire. They 



are found on the ground under stones, &c. Some {Scydmoenus) frequent damp places. We iniite 



them into one genus, — 



Mastigus, Hoff. 



Mastigus, has the antennae [elbowed], with the basal joint very long ; the last two joints of the maxillary palpi 

 form an oval mass ; the thorax is ovoid. M. palpalis, Latr. 



Seydnuetms, Latr., has the antennae scarcely elbowed, [the basal joint not being long] ; the maxillary palpi are 

 terminated by a minute pointed joint, and the thorax nearly globose. S. Helwigii, Latr. M. Duros discovered 

 .S^. clavattis, Gyll., in an ant's-nest, which tends to confirm my views of the relation of this genus with the 

 Pselaphi, at the end of the Brachelytra. 



In all the Clavicornes following, the head is generally received into the thorax ; and the maxillary 

 palpi are never porrected and clavate at the same time. The whole of their appearance exhibits other 

 distinguishing characters. 



The genus Hister forms our second tribe, named Histeroides. The four hind legs are wider apart 

 at their insertion than the two anterior, which character alone distinguishes tliis gen-us from all the 

 others of this family ; the feet are contractile, and the outer edge of the tibiae is toothed or spinose ; 

 the antennae are always elbowed, and terminated by a soHd mass, composed of joints very close to- 

 gether ; the body is of a very solid consistence, generally square, or parallelopiped, with the prosternum 

 often dilated in front, and the elytra truncate ; the mandibles are strong, advanced, and often of un- 

 equal size ; the palpi are nearly filiform, or slightly thickened at the tips, and terminated by an oval or 

 ovoid joint. In relation to their habits, the toothing of their tibiae, &c., these insects approach the 

 Coprophagous Lamellicornes ; but in other respects, chiefly anatomical, they naturally approach the Silpha;. 



These animals feed on cadaverous or stercorareous matters, rotten vegetable substances, such as 

 manure, old fungi, &c. Others reside under the bark of trees. They creep slowly ; they are of a 

 very shining black or bronzed colour. Such of the larva; as have been observed feed upon the same 

 substances as the perfect insects. Their bodies are of a linear form, depressed, nearly smooth, soft, 

 and of a yellowish white colour, with the exception of the feet and first segment of the body, of which 

 the skin is scaly, and of a brown or reddish colour ; it is furnished with six short feet, and terminated 

 behind in two articulated appendages and an anal tubular elongation ; the scaly plate of the first segment 

 is longitudinally channelled. 



This tribe exclusively comprises, as above said, the genus 



HiSTER, Linn. 

 Some of these have the tibiae, at least those of the fore-legs, triangular, and toothed on the outer edge ; the a: - 

 tennae always exposed and free ; the body generally square, and but little if at all thickened. 



2 L 2 



