June, I9IS-] HoOD AND WiLLIAMS : NeW ThYSANOPTERA. 127 



all others present, moderately long, conically expanded at tip ; posterior laterals 

 longest, distinctly longer and stouter than the posterior marginals. Pterothorax 

 not quite as wide as the prothorax, sides converging behind. Fore wings slightly 

 constricted in the middle where there is in mounted specimens a slight folding 

 of the surface ; transparent at base and apex, faintly clouded with brown in the 

 middle ; i to 4 accessory hairs on the posterior margin (thirteen counts gave 

 I three times, 2 three times, 3 five times, 4 twice) ; hind wings with similar 

 fold in middle, almost colorless. Fore tarsi armed with a strong curved 

 tooth, from the base of which arises two spines about equal in length to it. 



Abdomen normal ; lateral bristles pale and slender, some capitate (Plate 

 VIII, fig. 7). Tube abovit half as long as head, not twice as long as basal 

 width, and rather less than twice as broad at base as at apex ; terminal 

 bristles brown, almost twice as long as tube. 



Measurements of holotype : Length 1.5 1 mm.; head, length 0.192 mm.; 

 width 0.138 mm.; prothorax, length 0.135 mm., width (inclusive of coxa) 

 0.258 mm.; pterothorax, width 0.237 mm.; abdomen, width about 0.29 mm.; 

 tube, length 0.099 mm., width at base 0.059 mm., at apex, 0.031. 



Total length of antenna, 0.325 mm. 



Described from eight females, all from Florida, as follows : Or- 

 lando, November 5, 1914, one female taken on an undetermined plant 

 (possibly Mimosa), and three females from Spanish moss on pine 

 tree; Orlando, November 6, 1914, two females from bamboo; Or- 

 lando, November 8, 1914, one female from rushes; Emeralda, Novem- 

 ber 17, 1 91 4, one female from rushes. 



Immediately separable from all known species by the color, all 

 other described forms of the genus being uniformly either dark or 

 light. 



Zygothrips puUus new species. (Plate VIII., fig. i.) 



Female (macropterous). — Length about 1.5 mm. Color dark brown, with 

 tarsi, tibiae, apex of fore femora, and third antennal segment lighter ; tube 

 darker at base than at apex. 



Head about one and one-third times as long as wide, broadest at basal 

 third, thence gradually narrowing to eyes and to base, more rapidly in the 

 latter direction ; postocular bristles as long as eyes, capitate. Eyes about one- 

 fourth as long as head, not protruding. Anterior ocellus directed straight 

 forward ; posterior ocelli opposite anterior third of eyes. Antennae about 

 1.75 times as long as head, rather stout; segment i broader than long; 2 



