1925 ] 
New N eotropical Thysanoptera 
53 
uniform dark brown, somewhat darker than head, except seg- 
ment 3 which is pale brown, with pedicel and apex pale gray; 
wings brown, the fore pair without pale band at base, but with 
an indistinct, narrow, median, pale streak. Antennae 8-seg- 
mented; segment 3 decidedly less than twice as long as wide. 
Segment 10 of abdomen divided above. 
Trinidad; C. B. Williams; no further data. 
An undoubted Plesiothrips, remarkable for the distinctly 
eight-segmented antennae. 
Plesiothrips amblycauda sp. nov. 
Female (macropterous). — Length about 1.1 mm. Color 
brown, head darkest, prothorax with bright crimson subhypo- 
dermal pigmentation; femora brown, the fore pair yellow at 
apex; tibiae gray, fading to pale yellow apically; tarsi pale 
yellow; antennae dark brown, about concolorous with head, 
except segment 3, which has the pedicel and apex pale gray; 
wings dark brown, without pale band at base. Segment 3 of 
antennae more than twice as long as wide. Segment 10 of ab- 
domen not divided above. Ovipositor extremely minute, ves- 
tigial, entirely functionless; tip of abdomen rounded, rather 
than conical. 
Trinidad; C. B. Williams; on leaf of Arum lily. 
The long third antennal segment and the undivided tenth 
abdominal segment, together with the dark coloration, make 
this a very distinct species. It is a true Plesiothrips, with an- 
tennae presumably seven-segmented, though the extreme tips of 
both are missing in the unique type. 
Merothrips cognatus sp. nov. 
Female (macropterous). — Length about 1.0 mm. Very close 
indeed to M. fusciceps Hood and Williams, but with head 
smaller (width 0.105 mm.) and eyes larger, these prolonged on 
ventral surface to a point directly beneath posterior dorsal 
margin of head, and about, equal in width to their interval; 
tooth on fore tibia minute. 
