1G IIYMEXoPTEKA OF AMERICA. [PART T. 



This circumstance promises to render the study of the species 

 exclusively difficult. 



Division ZETHUS 1 (sensu strictiore). 

 (Sacss. Vespidea I, 9, III, 115.) 



Second abdominal segment subsessile ; expansion of the petiole 

 globular, lengthened. Thorax moderately lengthened. Meta- 

 thorax convex, presenting two rounded convexities, separated by 

 iove. Antennae of the males terminated by a spiral. The 

 6th abdominal segmenl bearing underneath two lamellar appen- 

 dages (copulative?). Species large, having a feeble sculpture, 

 lint not polished and witli a dull metallic color. 



It i> impossible not to be struck with the resemblance of these 

 insects to the Synoeca. The same form of head, indented be- 

 hind, the same dull metallic color, great size, pediculate abdomen, 

 mandibles almost the same form, etc. 



The representatives of these two genera inhabit also the same 

 countries of America. There ii», in their color and appearance, 

 one of those analogies which we sometimes find impressed upon 

 insects of the same regions of our globe,- and this seems especi- 

 ally (.ne of those openings that modern zoology should carefully 

 mark as suitable to cast some light on the relationship of species. 



1. Z. rtvt taJ«'op<>!amO Fabb. 



Vespa carule pennis Pabr. Ent. syst. Snppl. 203, 179S. 



us caruleopennis Fabb. S. P. 2^2, L— Latr. Gen. IV, 137; Encycl. 



pi. 393, fig. 12,13. -Sauss. Vespides, I, 9, 1 ; Revue Zool.X, 1858, (34. 



Zethus brasiliensis Sacss. Vespides I. 10,2, J; III, 115, % (prob. variety 



of this species ). 

 Zelkus magnus Saoss. Vespides I, 11, 4, pi. viii, fig. 5, $ . 



Abdominis petiolo globoso-clavato, sulco tenuissime partito. 



Eab. South America, Cayenne, Para, Brazil, Quito. 



1 I havi 1 from this division a certain number of small species, 



which have very much the same form of abdomen, but whirl, by their 

 olypeus and the angular fen, of the metathorax, find a more natural 

 a the division Zethui 



■ The Vespides of Chili present a yet more striking example of this. 

 See below Hypodynerus. 



3 The Vespa surinama Lixh. fGmel V °T",o em is a ;»i, ,. *i • 



v 'inn. > , -i jj, 4a) } i a either this species 



or a oynoeca. 



