126 MODERN CLASSIFICATION OF INSECTS. 
C. gallee tinctoriz) are distinguished by the gallivorous habits of the 
majority of the species; and by having the antenne straight, and 
13- to 15-jointed ; the wings with but few nervures; the palpi short ; 
and by the construction of the ovipositor. 
The head is of small size, and transverse; the thorax thick, and 
of an oval form; and the abdomen much compressed, ordinarily with 
a very short peduncle. The antennz are inserted in the middle of the 
face: they are generally of moderate length and slender (those of 
the females being shorter and thicker), varying in the number of 
joints (13 to 15) in the sexes, the males having one or two joints more 
than the females (fig.73. 16. ¢, 17. 2, antenna of Ibalia). The basal 
joint is thickened, the second very short, and the third the largest, 
and in the males often incised or curved ; the labrum is very minute; 
the mandibles (fig. 73. 13. C. quercus folii*) are short but robust, 
with several teeth at the extremity, somewhat differing in the oppo- 
site jaws; the maxille ( fig. 73. 14.) are elongate, horny at the base, 
and furnished at the extremity with a broad membranous ciliated 
lobe; the maxillary palpi are 5-jointed, the basal joint being very 
minute, and the terminal one somewhat securiform. The mentum is 
elongate, narrow, and horny; the labrum large, fleshy, and entire ; 
and the labial palpi 2- or 3-jointed, the terminal joint being somewhat 
oval, and pointed towards the tip (fig. 73. 15.). The mesothorax is 
large; the scutellum being very prominent, and often marked with 
several impressions: the wings have but few veins, the anterior 
having two basal cells (the interior being but slightly developed), one 
marginal cell, and two or three submarginal ones; the second of the 
latter, when there are three, being very minute: the under wings 
have only one strong vein. The abdomen is oval and very much 
compressed, the basal joint being the largest, the others (generally 
five in number) very short and scaling one into the other; the 
peduncle is ordinarily very short (fig. 73.18.) ; the ovipositor has 
been described as spirally convoluted, but its true composition has 
been overlooked by all previous writers. Neaumur, Latreille, and 
Burmeister have especially attempted the description of this organ; 
but in consequence of not tracing the analogies which the various 
parts present with those of Sirex, Ichneumon, &c, they have not 
succeeded in obtaining a correct view of its construction. On late- 
* Figs. 73. 13—21, 23 and 24, are from Cynips Quercus folii. 
