BIONOMICS AND DEVELOPMENT OF LYGOCERUS SP. 119 
TExt-Fiac. 17. 
The same as in figs. 15 and 16, shortly before metamorphosis. 
x 350. a.=anus. ct.=cuticle. dc. sh.=imaginal disk of sheath. 
dc. st.=imaginal disk of stylet. de.v.=imaginal disk of valve. 
gl. p.=‘ poison gland’. hp.=hypoderm.  s. 11.=sternite of seg- 
ment 11. 
still uncertain. The tubular gland, ‘ glande tubuleuse’, that 
Seurat describes in Doryctes, I have not traced in Ly go- 
cerus (figs. 14, 15, 16, 17). 
Owing to lack of suitable material, the whole ontogeny of 
the male genital armature was not followed, but it appears to 
arise, as described by Seurat, from the imaginal disks of the 
twelfth segment only. In the fourth instar two terminal 
lateral processes appear at the end of the disks, and probably 
represent the future stipites (forcipes) (fig. 18). 
