34 SYNOPSIS OF GENERA. 



45 (46) Scutellar foveas reaching to the middle of the scutellum ; 



radial area at the base, not curved ; the second and the 

 following segments finely punctured. Eubothrus. 



46 (45) Scutellar foveas not reaching to the middle of the scutellum ; 



radial cellule at the base sinuately enlarged. Liposthenus. 



47 (44) The second abscissa of the radius not curved ; radial cellule at 



the base and apex closed ; areolet present. 



48 (51) Radial cellule on the fore margin closed. 



49 (50) Mesopleuras striated; the first and second joints of the flagel- 



lum equal in length. Periclistus. 



50 (49) Mesopleurae alutaceous ; the first joint longer than the 



second. Phanacis. 



51 (48) Radial cellule open. 



52 (53) Mesonotum quite smooth. Xestophanes. 



53 (52) — not — Aulax. 



54 (43) The second abdominal segment striolated. 



55 (56) Radial cellule open. Sapholytus. 



56 (55) — — closed. Synergus. 



Obviously the discovery already alluded to by Adler 

 of the occurrence of alternation of generation in the 

 family upset the older genera, and made a revision in 

 view of the new facts imperative. This needful work 

 was admirably done by Professor Gr. L. Mayr, of 

 Vienna. His synopsis of the genera, so far as our 

 Fauna is concerned, is as follows : 



Synopsis of the Genera as defined by Professor Mayr*. 



Females. 



1 (4) Wingless. 



2 (3) Furrows of the par apsides complete; antennae 14-jointed ; a 



short, thickish keel between the antennas; head swollen 

 behind the eyes; ventral spine 1 — 1| times longer than 

 broad. Biorhiza. 



3 (2) Furrows of the parapsides incomplete; antennas 13 — 14-jointed; 



no keel between the antennae ; head not swollen behind ; 

 ventral spine 2 — 2-| times longer than broad. Trigonaspis. 



4 (1) Winged. 



5 (6) Petiole rugosely longitudinally striated ; the second and third 



abdominal segments without any visible suture ; face 

 obliquely striated; frontal keels usually reaching to the 

 ocelli ; radial cellule closed ; antennas 14-jointed. Synergus. 



6 (5) Petiole smooth, not striated ; frontal keels absent. 



7 (8) Face with two distinct parallel keels going from the antennas 



to the base of the clypeus; antennas 12-jointed; scutellum 

 with two foveas at the base ; third abdominal segment longer 

 than the second, closely united, but still with the suture 



* Die Genera der Gallen bewohnenden Cynipiden, Wien, 1881. 



