336 [May 



are .sharper and more protruding, which gives the scutellum a more 

 triangular shape." 



About Neuroterus Hartig says (1. c. TIT. p. 338), that it can be 

 divided into two groups, based on the presence or the absence of parapsi- 

 dal grooves; in the group without them, the mesonotum is an uninter- 

 rupted, smooth, very shining convex surface; as a general rule, the 

 mesonotum of this genus is more smooth and shining than in most spe- 

 cies of Andricus. It is remarkable, adds Hartig, that two so closely 

 allied genera as Andricus and .V' uroterus should be so different with 

 regard to their mode of reproduction. Neuroterus certainly belongs to 

 the agamous genera; in Andricus the males are as common as the 

 females. 



Other remarks of Hartig, bearing on the subject of classification, 

 are the following : 



1. (1. c. Ill, p. 323). All the genera, named on the analytical table 

 (page 5), are gall-producers (Psenidae) ; Neuroterus alone may some- 

 times be inquilinous; Aulax, which belongs to the following section, 

 he also refers in part to t. e Psenides. (I will discuss this question in 

 the introductory remarks to the second section.) 



2. {ibid.) All the above named genei'a are bisexual; with the ex- 

 ception of the following, which are agamous: Cynips, Apophyllus and 

 those species of Neuroterus. which an gall-producers; (the latter 

 circumstance is rather remarkable and perhaps suggestive ! Compare 

 above, page 334.) 



3. (1. c. IV. p. 408). Wingless females of Teras are often bred from 

 galls, together with winged specimens of both sexes ; such specimens 

 show a less developed thorax, but are however distinguished from Bior- 

 hiza Westw. {Apophyllus Hartig) by a larger scutellum. 



4. (1. c. IV, p. 411). Hartig introduces the new genus Synophrus, 



which was not included in the tabular arrangement given above. It 

 is characterized as follows: " Segmentum abdominis secundum* reli- 

 quia longius, area radialis augusta, areola basalis, anteuna? filiformes. 

 14 ( — 15 ? ) articulatje; palpi maxill. 5 articulati ; palpi lab. triarticulati. 

 articulis ultimis appendiculis parvis apiealibus; facies thoraciscjue latera 

 aciculata ; abdominis segmentum secundum * reliquis prominens." This 

 insect was obtained from a gall on Quercus cerris ; its second abdomi- 

 nal segment seems to have nearly the same structure as that of Synergus. 

 The extracts which I have just given, contain nearly all the infor- 



* Hartig has jmmum in both cases, but in accordance with the terminology 

 adopted by us, I change it to secunduvi. 



