DOLICHOFUS. 25 



male sex only. The systematic arrangement which follows the 

 dichotomic table subdivides the genus in groups, founded upon 

 easily perceptible characters common to both sexes. I think it 

 will be useful to retain these groups, or, at least, the principal 

 among them. 



Table for determining the Species. 



, f Prevailing color of the feet black. 2 



I Prevailing color of the feet yellowish. 9 



9 ( Cilia of the inferior orbit black. 3 



v. Cilia of the inferior orbit whitish. 4 



o f Face ochre yellowish. 1 gratus Lw. 



( Face silvery white. 2 laticorais Lw. 



. f First joint of hind tarsi with numerous bristles. 3 setifer Liu. 



\ First joint of hind tarsi with but few bristles. 5 



_ ( Hind tibiae black only at the tip. 6 



\ Hind tibiae quite black. 7 



f The black at the tip of the hind tibiae rather extended and not very 



sharply limited. 4 albiciliatus Lw. 



i The black at the tip of the hind tibias but little extended and sharply 



I limited. 5 xanthocnemus, n. sp. 



H ( A considerable extent of the tip of the femora yellow. 6 tetricus, n. sp. 



I The extreme tip of the femora only somewhat yellow. 8 



R f Lamellae of the hypopygium pointed. 7 acuminatus Lw. 



\ Lamellae of the hypopygium rounded ovate. 8 ovatus Lw. 



q ( Cilia of the inferior orbit black. 10 



I Cilia of the inferior orbit pale. 11 



^ ( Fore coxae blackish. 9 pachycnemus Lw. 



I Fore coxae yellow. 10 brevipennis Meig. 



, , f Tegulaa with pale cilia. 12 



I Tegulse with black cilia. 23 



, f Antennae black, at the utmost, the first joint almost red. 13 



I Antennas altogether, or at least their larger portion, yellowish red. 21 

 ./ Fore coxae dark beyond the middle. 11 longimauus Lw. 



I Fore coxse pale. 14 



, . f Tip of the hind tibiae decidedly blackish. 15 



I Tip of the hind tibias not or very slightly infuscated. 16 



1 , ( Fore tarsi only ferruginous-brownish. 12 brevimanus Lw. 



I Fore tarsi blackened from the tip of the first joint. 13 socius Lw. 

 , ( Hind tarsi entirely black. 17 



X Basis of the hind tarsi pale to a considerable extent. 19 



, - f Hind femora of the male not ciliated. 14 uudus, n. sp. 



\ Hind femora of the male ciliated. 18 



