28 Annals Entomological Society of America (Vol. VIII, 
Cephalothrips yucce (fig. 8 and 17).—In the nymph of 
Cephalothrips the clypeus (cl.) is a long, V-shaped, nearly 
symmetrical piece attached to the caudal margin of the front 
(fr.). The fronto-clypeal suture between the clypeus and the 
head-capsule is wanting. The small, distinct, convex piece 
at the distal end of the clypeus is the labrum (Ir.). The clypeus 
of the semi-pupal stage is smaller than that of the nymph 
on account of the reduction of the mouth-cone. It is sym- 
metrical and shows a distinct fronto-clypeal suture, but the 
clypeo-labral suture is not present, however, it is indicated by 
indentations on the lateral margins of the clypeus near the 
distal end of the mouth-cone. The ventral margin of the 
labrum is bilobed indicating its future adult structure. Within 
the semi-pupal parts the developing adult structures can 
be seen. 
In the adult (fig. 8) the clypeus and labrum have been 
modified thru the reduction of the mouth-cone, but they are 
distinctly differentiated by sutures and color differences. 
The above interpretation of the clypeus and labrum, which is 
the one given by Muir and Kershaw, agrees with the nymph 
and adult condition found in all Tubulifera observed and it 
also explains the condition found in the Terebrantia. Garman’s 
interpretation of the clypeus and labrum in the Terebrantia 
presents difficulties when an attempt is made to apply it to 
the conditions found in the Tubulifera. 
_ CompouND EyvEs.—The compound eyes of Heliothrips (fig. 
12, 13 and 19) are present in the nymph as small, oval areas 
on the lateral aspects of the head-capsule in the dorso-caudal 
region. There are five, round, indistinct bodies in each elevated 
area. In the nymph of Cephalothrips (fig. 17 and 18) two 
similar, elevated, small, oval areas are present on the cephalo- 
lateral aspects of the head, but these possess no facets or round 
bodies. In the adult stage of both species (fig. 1, 2, 5, 7, 8, 9, 
and 11) there is a large, reniform area filled with facets, cover- 
ing the latero-cephalic areas of the head. In the adult of 
Heliothrips the eyes protrude beyond the general curvature of 
the head, the facets are scattered, few in number and variable 
in size. From a ventral view six large, opaque facets can be 
seen. These larger facets retain their muddy brown color, 
and do not become clear and transparent as do the remainder 
