540 THE ENTOMOLOGIST. 



b. Scutellum not elongated, usually semicircular 



or cylindrical. 

 =;= Scutellum quite flat. - - - Anopedias. 



** Scutellum not flat, 

 t Head cubical. .... Isocybus. 



fi Head not cubical. 



I Scutellum with a hair-tuft at the tip. - Tbichasis. 



II Scutellum with no hair-tuft at the tip. 

 § Border of the abdomen with a very broad 



rim. - - . - - - Hypocampsis. 



§§ Border of the abdomen with no broad rim. 

 X Scutellum separated from the scutum by a 



deep suture. ... - Polygnotus. 



X X Scutellum not separated from the scutum by 



a deep suture. - - - - Platygastek. 



The genera are thus twenty-one in number, and, without 

 expressing an opinion whether they are or are not needlessly 

 numerous, a few remarks may be made on them wilh reference 

 to the British species which are included in them. Iphitra- 

 chelus, Inostemma, and Platygaster, are already known as 

 British genera. Allotropa is founded on Inostemma Mecrida, 

 Melaclisis on I. areolata, and Monocrita on I. Atinas. The 

 next genus,Isostasius,includesPlatygasterpunctiger,a species 

 that is of much importance in agriculture, by appropriating to 

 itself Cecidomyia Tritici, a fly that is very injurious to wheat. 

 The genera Acerota, Xestonotus, Isorhombus, Synopeas, and 

 Anopedias, may be passed over till more can be said of the 

 species which they include: these are not mentioned by 

 Foerster. The genus Piestopleura is founded on Platygaster 

 Catillus; Amblyaspis is represented by Platygaster Larides, 

 P. Nereus, and P. Roboris ; Leptacis includes P. Tipnlae, 

 P. Nydia, P. Laodice, and P. Nice; P. Craterus is the typical 

 species of the next genus Ectadius, which is followed by the 

 genus Saclogaster : in the latter there are two described 

 British species, P. Osacer and P. ventralis; and Foerster 

 mentions that he has four more, one of which is parasitic on 

 Cecidomyia Pisi : these four are very likely also British, and 

 therefore the characters of them are translated in anticipation 

 of their discovery. P. ruficornis, P. Erato, P. Matuta, and 

 P. Colta represent Isocybas; and Trichasis claims P. Pisis, 

 P. Remulus, and P. Didas. A species of Hypocampsis is 

 parasitic on Cecidomyia Strobi. P. striolatus is the type of 



