GENUS DIASTEOPHUS. 71 



13. Synergus THAUMACERA. 



Cynips thaumacera, Dal., Anal. Ent., 1823, 96. 



Synergus Klugii, Htg., Germs. Zeits., ii, 199. 



— luteus, Htg., Germs. Zeits., ii, 199. 



— carinatus, Htg., Germs. Zeits., iii, 348 (?). 



— thaumacera, Mayr, Verh. z.-b. Ges. Wien, xxii, 719, 



21 ; Thomson, Opusc, 796, 6. 



Black ; the antennae, head (except the vertex), and legs bright rufo- 

 testaceous ; alar nervures fuscous ; antennae thickened. The second 

 antennal joint is about as long as broad ; the third joint considerably 

 longer than the fourth. Front punctured or finely coriaceous ; meso- 

 notum transversely rugulose. Frontal laminae usually indistinct. 

 Mesopleurae aciculate. 



The <$ has the second antennal joint usually thicker than long; the 

 third greatly elongated and swollen, especially at the apex. 



Length 1—2, $ 1—3 mm. 



A well-marked species from the thickened antennae. 

 The coloration of the head, particularly in the ? , is 

 very variable, varying as it does from almost entirely 

 black to almost entirely rufo-testaceous, but in the 

 latter case the vertex is usually black ; the antennae 

 also may be infuscated at the base and the apex ; the 

 thorax and abdomen, too, may be more or less rufous. 



I have only' reared it from the galls of Biorhiza 

 megaptera and renum, but it is also known from the 

 galls of Cynips cerricola, And. singularis, A. cydonias, 

 Spathegaster baccarum, S. tricolor, S. nervosus, and 

 8. glandiformis. 



Common. 



Sweden, Germany, Austria. 



Genus Diastrophus. 



Diastrophus, Hartig, Germs. Zeits., ii, 186. 



Antennae, $ 13 — 14-jointed, $ 14-jointed. Cheeks without furrows, 

 more than half as long as the eyes. The face on each side finely striolate. 

 Mesonotum smooth, shining, glabrous ; the parapsidal furrows complete. 

 Scutellum separated from the mesonotum by a keel ; at its base are 



