469 
1864.] 
divaricate with the “ventral valve.” Dorsal joints of the abdomen free, except 
in certain genera the suture between the 2nd and 3rd dorsal and probably 
in Ibalia the suture between the 6th and 7th dorsal, which are connate. Tip 
of the 9 abdomen bluntly and widely rounded or truncate. Tip of the % ab¬ 
domen angular or subangularly rounded, and only when the terminal segments 
are retracted, truncate, joints 4—7 being each vertically narrower than the pre¬ 
ceding one. 
Habits, so far as known, gallivorous. 
Figitidae. Venter retracted within the abdomen with the suture below 
barely perceptible, entirely internal and invisible 'b except a minute por¬ 
tion of its tip, entirely so in 9 except the tip of the terminal joint (Fig. Ill, v), 
which tip is horny, vertically flattened, and acutely angular, and in close con¬ 
junction with the similarly shaped terminal dorsal joint forms an angular 
horny borer. Concealed between the dorsal and ventral pieces of this borer lie 
the ovipositor (Fig. IV, o) and its sheaths (Fig. IV, s). ‘ Sheaths of the oviposi¬ 
tor horizontally porrect. Dorsal joints of the abdomen free except the suture 
between joints 2 and 3, which is connate. Tip of 'b abdomen truncate, joints 
4—'7 being each vertically nearly as wide as the preceding one, except that 
joint 7 is often excised below and shows underneath it a small portion of the 
tip of the last ventral. 
Habits, so far as known, insectivorous. 
CyQipidse aod Figitidae differ from all other families of insects known 
to me in the imago having but a single pair of abdominal spiracles, 
which are placed laterally close to the base of the 7 th or what is appa¬ 
rently the last dorsal segment (Fig. V, There are many dipterous 
larvae (e. g. Midas) which have only a single pair of abdominal spiracles 
which are placed on the penultimate joint; but the images and pupae 
of these very larvae have the usual number of abdominal spiracles, i, e. 
one pair on each joint except the last. Authors do not appear to have 
hitherto noticed this anomaly. It will be shown below that there 
exists an 8th dorsal joint in 9 Cynips, and there is an 8th dorsal joint, 
cylindrical and armed on each side with a horizontal bristle, in % Cynips 
also, which is occasionally exserted but generally retracted within the 
abdomen. In Figitidae % 9 dorsal joint is entirely concealed 
by the 7th, which, as in Cynipidae % 9 , bears a basal, lateral spiracle. 
As there are the same number of dorsal joints in the Tenthredinidous. 
Uroceridous and Cynipidous abdomen, viz. eight, and as in the two 
former families the venter is 7-jointed, besides the terminal piece which 
bears the organs of oviposition, while in Cynipidae the venter has only 
6 joints, (Fig. I,) besides the terminal piece TFig. VI) which is here 
