514 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



0.99(0.90-1.13). Labial segments: I, 1.15(1.08-1.30); II, 1.66(1.62- 

 1.74); III, 1.43(1.33-1.74); IV, 1.01(0.98-1.05). 



Pronotum: Length-width ratio, 4.38(3.60-5.08) :7. 60(6.63-8.67). 



Scutelliim: Width-length ratio, 5.18(4.50-5.81) :4.88(4.27-5.42). 



Length of body: 13.30(11.62-14.61). 



Type data. — The type of this species was said by Amyot and Ser- 

 ville to have come from "Cayenne," French Guiana. Its present 

 location is unknown to the author. 



Specimens studied. — 10 males, 9 females: 



Trinidad: St. Benedict Mt., Tunapuna; September. 

 British Guiana: Bartica District; June, July. 

 French Guiana: Maroni River, St. Jean. 

 Brazil: Alagoinhas, HyutanahS, Santarom, Taperhina. 

 Peru: "Achinamiza"; December. 



Bolivia: Buena Vista, Ichilo, Santa Cruz, Provincia de Sara; November, De- 

 cember. 



Paraguay: Villarrica. 



Discussion. — As originally proposed, this name appeared in paren- 

 theses in a paragraph following the treatment of giganteus. This ap- 

 parently explains why several of the early workers overlooked it 

 during their studies. 



Genus Cyrtomenus Amyot and Serville 



Cyrtonunus Amyot and Serville, 1843, p. 90. 

 Syllohus Signoret, 1879, p. clx.xii. New synonymy. 



Diagnosis. — The lack of a distinct subapical stria from side to 

 side on the pronotum, the compressed posterior tibia on which the 

 spines of the posteroventral margin are longer and distinctly more 

 slender than those on the dorsal margin, and the simple second labial 

 combine to separate this genus from all others in the Western Hemi- 

 sphere. 



Description. — Size large, length of body 6.4-13.3 mm; shape oval, 

 widest distinctly posterior to midlength; dorsum strongly and venter 

 still more strongly convex. 



Head: Nearly or about two-thirds as long as wide, oblique, flat- 

 tened or convex above, with a distinct, marginal carina; juga equal to 

 or longer than clypeus, converging and sometimes contiguous in front 

 of the latter; margins rounded or sometimes triangularly produced 

 eitlicr side of apex (fig. 58); a submarginal row of seven to twelve 

 coarse punctures, each bearing a single long, tapering hairlike seta; 

 ocelli moderate to large, situated on or slightly behind a line connecting 

 hind margins of eyes, separated from eyes by less than twice the width 

 of ocellus; antennae 5-segmented, II usually shortest (equal to III in 

 marginalis) , III and IV often subequal, V longer or shorter than IV; 



