332 EUMENID.E. 



P. Apical 3 joints of maxillary palpi 

 very small ; viiiitod, distinctly 



long-er than the tJrd joint Odynerus, p. 300. 



b'. Labial palpi 3-jointed, plumed Ptkrochilus, p. 373. 



b. Second cubital cell petiolate Alastor, p. 374. 



Genus ZETHUS. 



Vespa, pt., Fahr. Ent. Stjst. Suppl. p. 263 (1798). 

 Zethus, Fabr. Syst. Piez. p. 282 (1804). 

 Eumenes, pt. Latr. Hist. Nat. xiii, p, 344 (1805). 

 Epipona, pt., Spin. Gay., Chile, vi, p. 248 (1851). 

 Calligaster, Sauss. Mon. Guep. 6ul. p. 22 (1852). 



Type, Z. cceruleopennis, i'abr. 



Kange. Neotropical and Oriental regions. 



Head somewhat wider than the thorax, emarginate posteriorly ; 



mandibles oblique at the apex, with large terminal teeth, short, 



scarcely forming a beak, the apices 



slightly crossing one over the other ; 



antennae inserted about the middle 



of the face, massive, the middle 



joints of the flagellum the thickest ; 



clypeus broader than high ; ocelli 



placed in a triangle somewhat 



anteriorly on the vertex. Thorax 



oval, pronotum anteriorly truncate ; 



the median segment posteriorly 



steeply sloped ; legs slight, short. 



AVings rather long and narrow ; 



p. ni v ,1. 7 7 o d radial cell of fore wing short, 

 Fig. 91. — Zethus dolosus, 9. |. , ^■ , j ai 



^ ' + 3 not reaclinig beyond the apex 



of the 3rd cubital cell, shortly appendicuiate ; 1st cubital cell 



equal to the 2nd and 3rd united on the cubital nervure, 2ud cubital 



cell at top about one-fourth of its length measured on the cubital 



nervure, 3rd broader at top than it is on the cubital nervure. 



Abdomen : the 1st segment produced into a petiole, which is 



attenuate at base and apex, broad and vertically flattened in 



the middle ; base of 2nd segment shortly petiolate ; remaining 



segments forming with the 2nd a broad oval, rarely withdrawn 



inside it. 



I have always found the species of this genus solitary, but have 



never come across the nest. Forbes (' A Naturalist's Wanderings 



in the Eastern Archipelago,' p. 72) states that the Javan species, 



Z. cyanopterixs, makes a large communal nest like the social 



wasps. 



Key to the Species. 



a. Ijec^s bright ferruginous Z. ceylo7iicus, p. 33 



b. Legs black Z. dolosus, p. 333. 



