BIONOMICS AND DEVELOPMENT OF LYGOCERUS SP. 117 
Trext-Fia. 15. 
Vertical section through the developing genital armature of a female 
larva of the fourth instar. x 350. a.=anus.  ct.=cuticle. 
de. sh.=imaginal disk of sheath, de. st.=imaginal disk of stylet. 
de. v.=imaginal disk of valve. gl. p.=‘ poison gland’. 
ovipositor, as far as they go, are substantially in agreement 
with those of Seuraton Doryctes gallicus. The stylets 
arise from the posterior ventral wall of the eleventh segment, . 
and the sheath and valves are derived from the reduplication 
of the imaginal disks of the twelfth segment. A tubular 
glandular structure is formed by constriction from the hypo- 
dermal cells at the base of the latter. In its origin and position 
it corresponds with that described by Seurat as ‘la glande a 
venin’. Whether this organ is actually a poison gland in the 
Ceraphronidae I am unable to say. Saunders, quoted by 
Woodward (Ashmead, 1), records that he was stung by a female 
