SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 10/ 



23. 

 SIAGONUM QUADRICORNE. 



Order Coleoptera. Fam. Staphylinidae Lat.t Leach. 



Type of the Genus S. quadricorne K. 



SiAGONUM Kirhy Introduction to Entomology. 



AntenncB half the length of the insect, pubescent and hirsute, 

 straight, articulated ; gradually increasing in size from the second 

 joint (which is smaller than the first) to the extremity; terminal 

 joint obovate. (f. 6.) 



Labritm exserted, transverse, bilobed, ciliated. (1.) 

 Mandibles of male much longer than the head, produced exter- 

 nally far beyond the apex, which has the appearance only of a 

 strong tooth, ciliated internally (2.) : of female, broad at their 

 base, hooked, very slightly produced externally. (2. a.) 

 Maxillce divided mternally, ciliated ; terminal process dilated, 

 rounded, composed of parallel, transverse ribs, detached at the 

 apex : Palpi 4-jointed, first joint small, last cylindric-ovate, ter- 

 minated by a globular gland. (3.) 



Men turn transverse, broadest at the base, lobed in the centre be- 

 hind, and obtusely pointed before : Palpi appearing 4-jointed, 

 all the joints corneous only at the base, last joint the longest. 

 Lip dilated anteriorly, bilobed, ciliated. (4.) 

 Head 7iot broader than thorax, icith a horn on each side before the eyes 

 in the males {vide the coloured figure) .-females without horns {fig.7 .). 

 Thorax narrowed behind. Elytra longer than broad. Abdomen it- 

 near, 6- and 7 -jointed. Legs very short and small. Tibiae ciliated in- 

 ternally, and serrated {except in the last pair) externally, spincd. 

 Tarsi 5-joinfed, last joint equal in length to the other four (.5. a fore- 

 leg). Wings long, broad, transparent, with only 3 short nerves at 

 the base. 



Quadricorne PLl.f. 3. Kirby and Spence's Int. to Ent. 



Depressed, shining, punctured ; antennae and abdomen pilose. 

 Head nearly black. Horns, mandibles, antennae and legs red- 

 dish brown. Thorax deep chesnut, quadrate, narrow behind ; 

 anterior margin rather convex in the centre, angles slightly pro- 

 duced, rounded, with a smooth line of colour down the centre. 

 Elytra chesnut colour, brightest towards the centre, with 2 

 branched and 2 simple-punctured striae on each. Abdomen 

 blackish, with the edges of the segments reddish brown. 



In the Cabinets of Mr. Kirby, Dr. Stephenson, and the Author, 



A FIGURE of Siagonum quadricorne was given in the 1st vol. 

 of the Introduction to Entomology hy Mr. Kirby, who took ft 



Fig. I. — Facsimile of page from first edition. 



