StapliylinidcB of the Amazon Valley. 379 



describes the antennte as ten-jointed. I find them, hoAv- 

 ever, to be certainly eleven-jointed, the basal joint being 

 short and very stout, and much concealed by the prominence 

 above its point of insertion. Erichson has also described 

 the tarsi as five-jointed, and the 4th joint to be minute. 

 On inspection, however, the tarsi appear at first to be only 

 four-jointed, but a more careful examination reveals the 

 fact that the tarsi are really five-jointed, and that the 

 4th joint is not minute, but consists of a very small basal 

 and articular portion, to which are attached two long 

 slender lobes, which are so closely applied to the 5th joint 

 as only to be detected by bending or lifting up the ter- 

 minal joint. 



Nothing is known as to the structtu'e of the labrum, 

 Avhich is quite invisible in the species. It is probable, 

 however, that it is concealed under the largely-developed 

 horny clypeus, and that it is moveable ; and that the tAvo 

 long spines which appear to proceed from the front of the 

 clypeus are in I'eality appendages from the labrum. The 

 sexual characters have hitherto escaped observation. I 

 have pointed them out in the following description of 

 M. spi7iosus, but should add that, though in iM. spinosus 

 the antennte are similarly formed in the two sexes, in some 

 of the other species there is a remarkable sexual disparity 

 in the structure of the apical joints. 



Seven species of the geniTS have already been described : 

 tAvo from Northern America, three from South America, 

 one from Australia and one from South Africa. The 

 species, hoAvever, are undoubtedly more numerous in 

 South America than elscAvhere, for I have thirteen species 

 from thence in my collection, Avhile the only other species 

 I have seen is the Australian one. 



1. Megalops spinosus, n. sp. Niger, nitidus, antennis 

 pedibusque testaceis, illis clava fusca; thorace transversim 

 quadrisulcato, sulco secundo medio vix, tertio sat late, 

 interrupto; elytris ante medium striola obliqua impressa. 

 Long. corp. 2 lin. 



Antennfie yclloAV, darker toAvards the extremity, Avith 

 the club fuscous; 3rd joint twice as long as 2nd, 4th 

 about as long as 2nd; 5— -7 each shorter than its pre- 

 decessor; 8th small, 9th a good deal broader than 8tli, 

 bead-like ; 10th rather strongly transAerse, 1 1th moderately 

 large, slightly broader than 10th, as long as 9th and 10th 



