270 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXIV 



insect, for which we erect the genus Euhexacentrus below. Redten- 

 bacher and Karny have misidentified material of mundus as 

 annulicornis, this apparently resulting in Kirby's placing the latter 

 name in the present synonymy. 



In the Malayan material before us the last two tarsal joints are 

 alone blackish, while in the Moluccan series the majority have all 

 of the tarsal joints blackish. The present large series, however, 

 shows this feature to be of no diagnostic value, a few Moluccan 

 individuals having only the last two joints dark, while a single 

 male of that series has the tarsi entirely pale, (these specimens 

 belonging to the same species beyond possible question). 



The color of the cephalic tibiae varies similarly, the majority of 

 the Moluccan series having heavy dark brown flecks at the bases of 

 the spines, a few intensive specimens have the external surface of 

 the tibiae solidly dark brown to near their apices, while a few re- 

 cessive examples have the tibiae with scarcely a trace of brown 

 marking. 



In the character of the presence of one or two dorsal spines on 

 the median tibiae, even greater variation occurs, as in some in- 

 dividuals before us such spines are absent on one side and present 

 on the other. Likewise the form of the male tegminal speculum 

 varies to some extent. 



EUHEXACENTRUS new genus. 



The present genus is erected to include a single species, E. an- 

 nulicornis (Stal). That species has apparently not been reported 

 since the original description, Redtenbacher and Karny having 

 mistaken Hexacentrus mundus (Walker) for it. 



The limb armament and short, serrulate ovipositor are among 

 the most important features to separate Euhexacentrus from Hexa- 

 centrus. Closer agreement in certain features is shown by the 

 Papuan Parahexacentrus paradoxus (Karny). 



Compared with unicolor Serville, genotype of Hexacentrus and 

 other species of that genus before us, the present genus is found to 

 differ as follows. Vertex similar, except that it shows a decided, 

 though linear, medio-longitudinal sulcus. Pronotum with trans- 

 verse sulci deeper and ventral margin of lateral lobes more lamellate 

 and sinuous. Tegmina and wings showing reduction, as in H. 

 japonicus (Karny), the latter differing in having the rounded apex 

 nearer the costal than the sutural margin. Ovipositor very short 

 and much heavier than in Hexacentrus, the dorsal margin weakly 

 sinuate, with a faint obliquity indicated toward the acute apex; 

 dorsal and ventral margins very minutely serrulate distad, un- 



