140 NEUROTERUS APRILTNUS. 



gall of Andricus noduli. Mayr bred Platymesopus 

 tibialis, Westw., from the galls. 



There seems to be some doubt as to the agamic 

 form of this species. Adler (Zeits. f . wissen. Zoologie, 

 xxxv, 200) suggested, from a certain resemblance and 

 from the form of the ovipositor, that it was Neuroterus 

 ostreus. Beyerinck, on the other hand (Beob. u. d. 

 ersfcen Entwick. einiger Cynipiden Gallen, p. 138), re- 

 lates that he has bred Neuroterus aprilinus from the galls 

 of Andricus solitaria. Von Schlechtendal (I.e.), how- 

 ever, concludes from his observations that Neuroterus 

 Schlechtendali, Mayr, is the agamic form, and this 

 view is further confirmed by the observations of Dr. 

 F. Loew. Again, there can be little doubt, as Mayr 

 has shown, that ostreus, being an Andricus, can hardly 

 be the agamic form of a Neuroterus. 



Sexual Form. — Black, shining ; mandibles, basal half of the antennae 

 and legs rufo- testaceous ; the apical half of the antenna?, the femora 

 and tibiae infuscated ; the coxae fuscous ; the antennse 13-jointed ; the 

 second antennal joint ovate and equal in length to the first ; the third 

 a little longer than the fourth ; the front, vertex, mesonotum, and 

 abdomen polished and very shining; parapsidal furrows abbreviated or 

 obsolete ; scutellum punctate, rugulose, in front in the middle some- 

 what smooth (Mayr). ? . 



Length 09 — 1*1 mm. 



Mayr says that the thirteenth joint in some specimens 

 appears to be composed of two amalgamated. 



The gall is very small, and is found on the oak 

 catkins in May. It is 1 mm. in length, contracted at 

 the base, dilated from a little below the middle 

 through a stout keel, which proceeds from there to the 

 top of the gall, where the keels become contracted. 

 The part surrounded by the two keels is somewhat 

 triangular. They are flattened laterally; when fresh, 

 green and bare, becoming brownish with age. The 

 part of the catkin from which they spring is dilated. 



Not very common in England and Scotland, Ger- 

 many, Austria. 



