of the Genus Golofa. 137 



in an arbitrary way, especially as it is not at all certain 

 from the description of the thoracic horn {'' rarius hoc cornu 

 palmatum est'') that it is not compiled from examples of 

 more than one species. In this hardly-to-be-dissipated 

 uncertainty it seems to me best to adopt the conclusion 

 ■uhich involves the least confusion, and as the figures and 

 references of later writers generally agree in applying the 

 name claviger to the S. American species (although the 

 thoracic horn is " palmate '^ par excellence), I prefer to adopt 

 that view. The males of these three species may be briefly 

 distinguished as follows : — 



Prothorax strongly punctured pizarro, Hope. 



Protborax very finely punctured. 



Elytra very deeply and uniformly punctured .... gidldinii, Hope. 



Elytra lightly and unequally punctured daviyer, L. 



The thoracic horn in all the specimens of G. claviger I 

 have seen is more massive than in the other species and 

 produced into three long and sharp points. All the species 

 of Golofa, however, are very inconstant and difficult to define, 

 and I have found the genitalia afford the most valuable 

 distinctive marks. 



The second described species is Golofa cegeon, Drury, of 

 which also the habitat was uti known to its describer and 

 the type is untraced. Latreille and Guerin assigned the 

 name to a Peruvian species and were followed by Burmeister, 

 while Erichson considered the Colombian insect called 

 G. porteri by Hope to be Drury^s species, and named that 

 figured by Latreille and Guerin G. humboldti. Fabricius 

 and Olivier seem to have known the insect only from Drury^s 

 " Illustrations," and it is curious that both Drury and Olivier 

 describe the scutellum as black and the thorax black-spotted, 

 but omit these details from their figures. The black scutellum 

 is, on the whole, in favour of G. humboldti, but the closely 

 similar G. eacus, Burm., is almost equally probable. The 

 " olive-brown " hair of the abdomen mentioned by Drury 

 is perhaps rather less inapplicable to G. jjorteri, but the 

 "short thick horn" of the thorax seems to exclude it. Here, 

 again, the line of least disturbance, although little else, 

 a|)i)cars to point to the Peruvian species. This species is 

 distinguishable from the Colombian and Venezuelan G. eacus 

 by the sides of the elytra being more dilated in the male, 

 the prothorax less punctured, more convex in front of the 

 horn, and the latter directed more backwards and rather 

 more strongly bent at the end. 



Burmeister's G. pelops is not, in my opinion, specifically 

 distinct from G. eacus, examination of the genitalia giving 



