259 . 
BOLBOCERAS MOBILICORNIS. 
7r 
Order Coleoptera. Fam. Geotrupidae Lat., Leach . 
Type of the Genus Scarabseus mobilicornis Fab. 
Bolboceras Kirby, McLeay. — Odonteeus Meg., Dej., Sturm. — Sca- 
rabseus Fab., Marsh., Gyll. 
Antennae inserted under the nasus and before the eyes, capitate, 
lamellate, 1 1 -jointed, basal joint long, producing very long hairs 
on the inside, 2nd joint large, cup-shaped, the 6 following short 
and rather transverse, the remainder forming an oval mass horny 
outside, coriaceous within, the 9th joint being the largest, the 
terminal one the smallest, appearing sliced off and porous at the 
apex (6). 
Labrum transverse, sides rounded, slightly emarginated and ci- 
liated, with long curved, spiny bristles (1). 
Mandibles corneous, small, curved, one with a rounded shoulder 
on the outside, apex bidentate, internal side emarginate, with a 
portion membranous and ciliated (2), 
Maxillae minute, terminated by a horny articulated ovate lobe, 
producing a few curved bristles, 2 horny teeth on the inside, the 
upper one slightly bifid. Palpi longer than the maxillae, 4-joint- 
ed, 1st and 3rd joints small, the former slender, 2nd longer ob- 
trigonate, 4th very long, subovate (3). 
Mentum subquadrate covered with long pubescence. Lip trans- 
verse, horny, deeply cleft in the centre. Palpi attached to small 
scapes, triarticulate ; basal joint minute, 2nd long pilose subcla- 
vate 3rd a little longer, elongate -oval, terminated by a gland (4). 
Head small, producing a long erect horn in the male. Thorax large 
cor nut ed in the males, simple in the females (8). Scutellum trian- 
gular. Elytra very convex and short. Wings ample. Tibiae curved, 
spined and spurred, anterior compressed, serrated on the external 
edge and producing a long obtuse spine at the internal apical angle 
(5). Tarsi long, 5 -jointed, basal and terminal joints of equal length, 
4th minute. Posterior tibiae dentated and spined ; terminated by 2 
spines, one of which is very long in the hinder pair. 
Mobilicornis Fab. Ent. Syst. v. 1 . pars 1 . p. 15. n. 43. — testaceus 
Oliv. — Fab. E. S. 1. 27. 83. var. 
Male, Castaneous black, shining. Palpi ochreous, head and tho- 
rax punctured, the former with a long moveable horn at the 
base of the nasus, the latter with a groove in the centre with a 
tooth on each side to receive the horn, a broad strong tooth on 
each side near the anterior and 2 foveae near the posterior angles. 
Each elytron with 14 punctured striae. Legs castaneous. Un- 
derside testaceous, pubescent. 
Obs. Some specimens are entirely testaceous $ the males are fre- 
quently smaller and have their horns much shorter than in the 
variety figured. The females have no horns. 
In the Author's and other Cabinets. 
