2G6 DYNASTIXJs. 



2 . Not shining above ; more ovate, less convex, with the head 

 and thorax entirely unarmed and the legs shorter. 



One very variable species is our only known representative. 



243. Chalcosoma atlas. (Plate II, fig. 12 (male).) 



Scarabfeus atlas, Linn., Si/st. Nat. i, 1858, p. 34o, Mm. Liid. Ulr. 



Beg. 1704, p. 6 ; Bimn., Hn7iflb. Ent. v, 1847, p. 270 ; Blanch., 

 Voy. P6le Sud, Zool. iv, 1853, p. 106, pi. 9, f. 1. 

 ScarabcTus chiron, Oliv., Entom. i ^3), 1789, p. 18, pi. 25, fio:. 217 ; 



Guerin, Voyage de Belanyer aiuv Indes Orient. 1834, p. 483, pi. 1, 



Ijg. 1. 

 Geotnipes Caucasus, F., Syst. E/eut. i, 1801, p. 10. 

 Dynastes kirbyi, Hope* Gray's Zool. Misc. 1831, p. 23. 

 Dvnastes liesperus, Erichs., Nov. Act. Leap. Car. xvi, Suppl. 1834, 



p. 238, pi. 37, tig. o. 

 Chalcosoma phidias, Blanch., Voy. Bole Sud, Zool. iv, p. 107, pi. 9, 



tigs. 2 & 3. 



Black, with the elytra, and frequently the prouotum of the male, 

 deep metallic green or coppery ; the lower surface brownish. 



d . Very massive and exceedingly smooth and brilliant above, 

 with long and slender legs. The clypeus is strongly bidentate and 

 the ridges in front of the eyes are large and prominent. The head 

 is armed with a slender pointed horn, curving forward and upward 

 and more or less compressed behind. At its full development it is 

 longer than the head and prothorax together, and rather sharply 

 curved near the middle. The posterior edge is generally provided 

 with a laminar projection on each side before the apex, but these 

 may be absent or represented by a fine serration. There is some- 

 times also a strong tooth near the middle of the horn. The 

 pronotinn is strongly narrowed in front, generally produced into a 

 sharp horn in the middle of the anterior margin, greatly elevated 

 above and produced at the sides into a pair of slender, acute, nearly 

 horizontal horns of vcny variable curvature, but in large specimens 

 enclosing three-fourths of a circle. The pronotum is considerably 

 narrower behind than the elytra and is sometimes strongly punc- 

 tured at the sides, but the punctures may become partly or wholly 

 obliterated. The scutellum is broad and irregularly punctured or 

 smooth. The elytra are devoid of punctures and very glossy. 

 The 2'ro2J?/(/u/iM?u is closely punctured and the jn/( /id ium and the 

 sides of the metastemum and abdomen are finely granulated and 

 clothed with miinite erect setic. All the tarsi are elongate but 

 especially the front ones ; the front tibia is slender, the two 

 uppermost external teeth rather far apart and the lower face armed 

 with a row of short perpendicular teeth ; the front femora have 

 each a small anterior tooth. 



In males of minor development (var. Icirbyi) the cephalic 

 horn is shortened in its apical part and the subapical lamina? 

 become more prominent antl divergent, forming with the apex a 



