1925 ] 
New N eotropical Thysanoptera 
61 
with prominent pointed bristles at posterior angles only, the 
outer pair much longer than prothorax. Fore tarsus unarmed. 
Tube more than half as long as head, nearly as wide at base as 
long (!). 
Male (apterous). — Like female in all essential respects, but 
smaller. 
Trinidad; C. B. Williams; on faggots. 
Easily known by the seven-segmented antennse, long- 
bristles, exceedingly short and broad tube, and the coloration of 
the legs and antennse. 
Plectrothrips impatiens sp. nov. 
Female (macropterous). — Length about 1 .7 mm. Prothorax 
with midlateral and anterior marginal bristles longer than post- 
oculars. Antennal segments 3-5 each with five (!) sense cones, 
6 with three. 
Trinidad; C. B. Williams; on cacao leaf. 
The only species of the genus with well-developed midlateral 
and anterior angular bristles on the prothorax, and the only one 
with more than three sense cones on any antennal segment. 
Pristothrips gen. nov. 
(777KST1?, a saw; OpL\f/, a wood worm.) 
Head much longer than wide, cheeks with one or two strong- 
bristles at basal third or two-fifths; eyes large, much wider than 
their interval, reniform as seen from above and very closely 
facetted; intermediate antennal segments moderately elongated, 
clavate, sense cones not unusually long; mouth cone slender, 
long and pointed. Fore femora enlarged in both sexes, always 
with a large subapical tooth on inner surface, sometimes with a 
row of small teeth basally; fore tibise with several (3-8 in the 
two known species) strong teeth on inner surface; fore tarsus 
with one long tooth. Wings broad, narrower apically, not cons- 
tricted at middle, without venation. Tube' shorter than head. 
Genotype : Pristothrips aaptus sp. nov. 
