HYMENOPTERA.— TENTHREDINIDE. 93 
The wings are of ample size, with numerous complete cells *, and 
a large stigma; the legs are of moderate length ; the posterior tibiae + 
are spurred in the middle in some genera ; the calcaria are of various 
shapes ; and the four basal joints of the 5-jointed tarsi (fig. 69. 10.) 
generally furnished beneath with small membranous appendages, 
which in some species resemble minute cups (fig. 69. 11.). In the 
male Cimbices, the basal-joint of the four posterior tarsi is produced 
into a spine beneath, and clothed with wool (fig. 71.1., hind leg, 
Cimbex, ¢ , showing the 2-jointed trochanter). The abdomen is sessile, 
subcylindric, and terminated in the females on the underside in a 
pair of compressed sawlike plates, applied against each other. These 
organs are curved upwards, and each is formed of two distinct por- 
tions, namely, the saw itself and the back support; the lower edge 
of the saw is finely denticulated and its upper edge is received in a 
groove on the under and thickened edge of the support, which is a 
flattened piece, also serrated on the upper edge, and which acts not 
unlike the back of a common saw. ‘These organs are also obliquely 
ribbed, so that they present a very elegant appearance. When at rest 
these organs are received between another pair of larger and flattened 
plates or valves, articulated in the centre; a pair of minute pilose styles 
is also attached’ to the extremity of the last abdominal segment on 
each side, which has been overlooked by Entomotomists {, but which 

cedes this “incision” bears a pair of spiracles (Burmeister Manual, pl. 12. No. 1.1 8.) 
In p. 264., of the same work he had however as expressly said that the metathorax 
“est tres court, ne forme qu’ un arceau supérieur, et il est ordinairement intimi- 
ment uni avec le premier segment de l’abdomen,” which last presents two spiracles ; 
and consequently, that the peduncle in those species in which the abdomen is pedun- 
culated, is the second abdominal segment ; the latter theory being adopted from the 
views of M. Audouin, as above noticed, in the general observations upon the order. 
It is true, that in many Saw-flies the hinder portion of the metathorax, notwithstand- 
ing its peculiar character (slit or excised), has so much the appearance of a segment 
of the abdomen, that the correctness of the above observations will be called in 
question. If denied, however, we shall be compelled to adopt the still less tenable 
theory of Audouin and Latreille. Saint Fargeau has indeed ventured to overcome 
the difficulty by rejecting both theories, considering (Hist. Nat. Hym. p. 4.) this 
hinder part of the metathorax as abdominal in the Sessiliventres, and (Ibid. p. 78.) 
as thoracic in the Pedunculiventres. 
* Jurine asserts that the number of cells in the wing of the imago is regulated by 
the number of prolegs in the larva. 
+ I possess an anomalous undescribed genus of this family from Africa, entirely 
destitute of calcaria. 
¢ Except by Mr. Newman, who, apparently [unaware of their general existence, 
has named a genus in which they are prominent Euura. 
