302 Mr. F. Smith's Descriptions 



rest of the segments with their margins constricted ; the 

 apical mucro stout and curving upwards beyond the 

 apical segment. 



Hab. — Shanghai. 



This insect was presented to me by H. De Rivaz, Esq. 



Fam. SCOLIID^. 



Genus Ptekombeus. 



Head wider than the thorax^ subglobose ; eyes lateral 

 and oblong-ovate ; antennae filiform, inserted on each side 

 of a bituberculate prominence in the middle of the face; 

 the scape obconic, the first joint of the flagellum globose, 

 and inserted in a cavity at the apex of the scape, the 

 following three joints of about equal length, the remaining 

 ones slightly decreasing in length to the apical one. 

 Thorax elongate, the prothorax produced anteriorly into 

 a short neck, its posterior margin extending backwards 

 to the insertion of the wings; the metathorax oblong, 

 its apex rounded ; the anterior wings with one elongate 

 marginal cell pointed at its apex; three submarginal cells, 

 the first nearly as long as the two following, the second 

 quadrangidar, and, narrowed towards the marginal; the 

 third obliquely quadrate ; legs moderately stout, with the 

 tarsi long and slender. Abdomen elongate, petiolate, 

 its apex pointed and terminated by an acute style, the 

 aculeus exserted. 



This genus is founded upon the characters of one sex, 

 and those characters are so anomalous, as to leave upon 

 my mind considerable doubt as to the correctness of 

 determining it to be the female ; the antennae are twelve- 

 jointed, and the abdomen is furnished with a sting, these 

 are, no doubt, the normal characteristics of the female, but 

 the abdomen is composed apparently of seven segments ; 

 it has undoubtedly seven distinct plates above, whilst 

 beneath the number is only six ; I have therefore regarded 

 the apical dorsal plate as a sheath or component part of 

 the exserted aculeus. That the insect belongs to the 

 Scoliidce, I think is certain ; the prolongation of the thorax 

 to the insertion of the wings, and a similarity of the 

 neuration of the latter to that of Myzine, induce me to 

 place it next to that genus. 



