1865.] 367 



time and have accidentally lost, since then, the only specimen which I 

 had reared from the gall of C. q. futilh 0. S. 



Genus CEROPTKES. 

 This genus is easily distinguished by an impressed, transverse line. 

 dividing the second abdominal segment into two portions, which are sub- 



O CD L J 



equal in length in the male, and the anterior of which is much shorter 

 than the posterior in the female. A very close attention is often re- 

 quired in order to perceive this line, which otherwise seems to be a 

 good distinctive character. Whether this line really represents a con- 

 nate suture I am unable to say, as the decision of this point would re- 

 quire a dissection which I cannot now undertake. 



Although the second segment (considered as a whole, as if the suture 

 did not exist) is very large in comparison with the others, it does not, as 

 is the case with Sj/nergus, entirely conceal all the following segments; 

 these project more or less considerably beyond the posterior edge of the 

 second segment, so that the segments three to seven can be easily 

 counted in some specimens; in others, however, they are more con- 

 tracted. The first abdominal segment is very short, projecting only a 

 little, in the shape of a rim, over the anterior edge of the second seg- 

 ment, and not at all tubular and striated, as in Synergus. Another im- 

 portant difference from the latter genus consists in the length of the 

 sheaths of the ovipositor, which project very considerably above the 

 dorsal line. Ceroptres pisum (). S. is the only species having, appa- 

 rently, very short sheaths; but I am not certain whether they are really 

 so, or only broken off in the only specimen of that species which I pos- 

 sess. The basal portion of the second abdominal segment is usually 

 more or less downy. The polished surface of the pleurae is perfectly 

 smooth and shining in all the specimens in my possession, or aciculate 

 on its lower part only, whereas it is more or less aciculate in all the 

 species of Synergus which I have seen. As Hartig. however, places 

 Ceroptres among the genera with aciculate pdeurae,^ as may be seen 

 on the analytical table of page 862. this character is probably not 

 one of general application. The antennas are 15-jointed in the male 

 and usually 12-jointed in the female; the last joint in the female is 

 very elongated, fully equal to the two preceding joints taken together; 

 occasionally this joint is subdivided in two joints by a distinct suture, 

 and then the antenna} are apparently 13-jointed. Ceroptres pisum has 

 13-jointed antenna? and the last joint is subdivided into two joints. Har- 

 tig calls the antennas 14- ( % ) and 13- ( 9 ) jointed In some of the 

 species the antennas are very slightly incrassated on their latter half; 

 in others this character is not perceptible. I think that Hartig gives 



