132 GENUS SIEEX. 



ments. On the ventral side it occupies fully half of 

 the total surface. The seventh segment has no ven- 

 tral continuation. The anus has its exit in the apical 

 spine. 



The larva is fleshy, cylindrical, colourless, with 

 fourteen segments, and provided with short stumpy 

 legs, in which the usual divisions are almost obliterated. 

 The head is smooth, shining, eyeless; on each side 

 above the clypeus are short, nipple- like, thick, appa- 

 rently biarticulate antennae. Clypeus slightly pro- 

 jecting, narrower towards the apex, which is trans- 

 verse ; labrum of the same form as the clypeus, but 

 smaller. Mandibles broad, quadrate, and unlike each 

 other, the right having a large lobe on the inner and 

 four short teeth on outer side ; in the left the basal (or 

 inner) part has no teeth as in the right, but it does 

 not project ; at the apex are four blunt teeth. The 

 left is hollowed throughout at the apical half, the right 

 only obliquely at the inner side behind the toothless 

 part. The right lies against the left, which projects 

 in front of it when at rest. 



Lower mouth organs small, thick, and fleshy. The 

 maxillae have on the outside short, stumpy, two-jointed 

 palpi, originating from a projecting basal lobe; the 

 outer lobe is broad at the base, and terminates in a pro- 

 jection not unlike a palpus. This is regarded by West- 

 wood (Int., ii, p. 116) as the real palpus, but I think it 

 will be admitted, by comparing it with the maxilla of a 

 Tenthredo larva, that it is really the outer lobe ; what 

 I consider to be the palpus, Westwood states is " very 

 minute and exarticulate ;" which is not the case, it 

 being more than half the size of the outer lobe, and is 

 most clearly biarticulate in all the specimens I have 

 examined. The inner lobe is thinner and sharper than 

 the outer, but is thicker at the base ; the top is rounder, 

 and the biting edge is provided with some brownish 

 setae. The labium is fleshy, thick, produced above 

 considerably, and bearing short, stumpy, two- (or per- 

 haps three-) jointed palpi. 



