116 
Psyche 
[December 
and denticulate. Labrum bilobed ; breadth about twice 
the length ; anterior surface of each lobe with seven minute 
hairs and/or sensilla; ventral border of each lobe with 
two contiguous sensilla and numerous rather long isolated 
spinules; posterior surface spinulose, the spinules near 
the lateral borders isolated and rather long, the remainder 
minute and in numerous subtransverse rows; posterior 
surface of each lateral lobe with two isolated and a cluster 
of four sensilla. Mandibles heavily sclerotized; moderately 
long and narrow, slightly curved medially; apical tooth 
moderately stout, slightly curved and round-pointed; two 
moderately stout teeth projecting inward from the inner 
border; a small patch of minute spinules (in short rows) 
on the inner surface just above the middle. Maxillae with 
a slight lateral swelling bearing the palp and a paraboloidal 
apex bearing the galea ; apex spinulose, the spinules rather 
long and in short rows, elsewhere short and isolated; palp 
digitiform with one lateral (bearing a spinule) and four 
apical (two encapsulated and two with a spinule each) 
sensilla ; galea digitiform with two apical sensilla. Lab- 
ium large, with all surfaces spinulose, the spinules in short 
subtransverse rows; palp a low knob with five apical sen- 
silla (three with a spinule each) ; an isolated sensillum 
on each side of the opening of the sericteries; the latter 
a short transverse slit. Hypopharynx spinulose. (Material 
studied: two larvae from British Guiana, courtesy of Dr. 
Neal A. Weber.) 
Genus Rhopalothrix Mayr 
Thorax and first two abdominal somites forming a stout 
neck which is strongly curved ventrally; rest of abdomen 
much plumper; posterior end broadly rounded. Body hairs 
numerous, denticulate and of two types: (1) slender, 
flexible, short to moderately long; (2) stout, slightly curved, 
with hooked tip, in a narrow irregular band around the 
middle of each somite. Labrum small. Mandibles with 
two medial teeth, the subapical small, the proximal large; 
with three or four denticles on the distal half of the poste- 
rior surface. Maxillae large; palp with five sensilla. 
