fnsects. 9833 



those of the posterior pair being more blackish, especially at the 

 tarsi. The length of the insect hardly reaches 5 raillimetres. 



Fig. 9 represents the very simple saw and ovipositor. 



On being touched these insects do not generally fly away, but draw 

 in the antenna? and legs against the ventral surface, and, rolling along 

 the leaf, allow themselves to drop to the ground, where they remain 

 still for a ie\v moments, until they think the danger has passed. 



The parasite, which I obtained from the cocoon, was an undescribed 

 species of Ichneumon, belonging to Gravenhorsl's first section, having 

 the scutellum and abdomen entirely black. 



Cladius uncinatus. King. 

 Imago : — Hariig, Blatt-und Holzwespen, p. 176, No. 3. 



Cladius ater subnitidus, pedibus rufo-flavis, exceptis coxis, apo- 

 physis omnibus, nee non parte antica femorum anteiioruin, quae 

 nigra sunt, articulis tarsorum ultimis et alis nigricanlibus. 



As long ago as 1844 I published a description of the larva of this 

 species in the ' Tijdschrift voornatuurlijke geschiedenis en physiologic' 

 (vol. xi. part 2). Since that time I have nearly every year met with 

 the insect in the month of September, and observed some varieties of 

 the larva ; but I have not as yet been able to find the larva in its 

 earliest stage, all those which I have seen being full grown. I imagine 

 the young larvae live at the tops of old elm-trees, and that only at a 

 late period of their lives do they descend the stems : if this be so it is 

 only by some chance that we can become acquainted with the earliest 

 stage of the larva. 



The full-grown larvae are to be met with in the month of September 

 on the stems of the elm, where they spin up in the crevices of the bark. 

 They are also frequently to be met with on stone posts standing 

 among elm-trees : thus I find them every year in some numbers on the 

 stone posts along the sides of the road between Leyden and Leijder- 

 dorp. Plate 4, fig. 1, represents a larva, magnified. They are 

 yellowish clear green ; 1 .5 centimetre long, and rather broad in propor- 

 tion to their length. Head very pale green, with a brown or black 

 square spot on the vertex ; this spot is divided into two equal parts by 

 a fine pale green line. The eyes are black, and placed in round black 

 or brownish spots ; on the clypeus is generally found a small blackish 

 irregular mark; the trophi are brown, varying in tint; the upper 

 surface of the head is thinly hirsute (fig. 3). The whole body is flatter 

 and broader than is generally the case with sawfly larvae. Along the 

 VOL. XXIII. 3 M 



