23 
| 2a bys Na bl Oop 
DESCRIPTIONS OF SOME EXOTIC SPECIES OF SAWEFLIES. 
Tue family Tenthredinide is one of great extent, and is distin- 
guished by the peculiar structure of the ovipositor, which is con- 
structed so as to act like a pair of saws in forming channels in the 
bark of twigs and ribs of leaves, in which the eggs are deposited. 
The caterpillars are also remarkable as being the only Hymeno- 
pterous larvee furnished with prolegs, thus resembling the caterpillars 
of the Lepidoptera. The insects figured on the opposite plate present 
some striking instances of departure from the general characteristics 
of the family or those particular groups to which they belong. 
Figure 1 represents the female of Perga Lewisii, Westw. (Trans. 
Ent. Soc. 1. p. 234), a species discovered in Van Diemen’s Land, 
by Mr. R. H. Lewis, who observed its singular economy. ‘ The 
maternal solicitude of insects for their offspring,” observes the 
writer, “has been seldom observed to extend beyond the various 
contrivances which instinct directs them to make at the time of the 
deposition of the egg, the female insect dying in most cases im- 
mediately after*.” The female Perga, on the contrary, after de- 
positing her eggs in a longitudinal incision between the two surfaces 
of the leaves of one of the gum trees (Hucalyptus), sits on the spot 
until the exclusion of her young, upon which, when hatched, she sits 
with outstretched legs, preserving them from the heat of the sun, 
and protecting them from the attacks of enemies, with admirable 
perseverance. From the various experiments with the insects and 
their broods, described by Mr. Lewis in his paper in the Transac- 
tions of the Entomological Society, it is quite evident that the 
female insect constantly watches over the young until death termi- 
nates her own existence. 
HYLOTOMA (Schizocera) australis, W. (Plate 7, fig. 2.) Late cyanea, ore maculisque 
duabus pone oculos fulvis; alis fascia lata pone medium fuscis; abdomine transverse 
striatulo, alis anticis et posticis cellula marginali appendiculata ; tibiis posticis calcari medio 
instructis, pedibus nigris, tibiis tarsisque anticis anoque fulvis ; antennis nigris. Long. 
corp. lin. 3. 
Habitat in Australasia occidentali. D. Gould. In Mus. D. Hope. 
This species differs from all the Schizocerous Hylotome described 
* In social insects, the honey-bee, for example, the care of the young devolves upon a parti- 
cular portion of the community allotted for that purpose (the neuters or workers), which are 
incapacitated by their structure from having any offspring of their own. 
