132 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



FAMILY THRIPID^ HALIDAY. 

 Genus MEROTHRIPS nov. 



(/xijpos, the femur; Qprf, a wood worm.) 



Head rather elongate, anteriorly obtusely angulate, with a pair of long 

 bristles on dorsum between eyes and antennae. Eyes (in the type species) 

 greatly reduced; ocelli wanting. Antennae long, approximate, eight-seg- 

 mented, moniliform, inserted on ventral surface of head; segments 3 and 4 

 with sense areas (instead of sense cones) at apex; segment 8 elongate, fusi- 

 form. Mouth cone equal in length to face, semicircularly rounded at apex; 

 maxillary palpi three-segmented; labial palpi two-segmented. Protho- 

 rax trapezoidal, broader than long and somewhat longer than head, with 

 a pair of subparallel longitudinal sutures separating the notum from pleu- 

 ron and coxa; posterior angles with a single long bristle. Legs very stout; 

 metacoxee separated by less than their own diameters; mesocoxae separated 

 by an interval thrice as great; fore and hind femora greatly enlarged; male 

 with a broad subbasal tooth on inner margin of fore femur and with a 

 long, stout tooth on inner margin of fore tibia at tip. Abdomen moderate- 

 ly slender, exceedingly blunt at tip, the apical segments very transverse 

 and with long, weak spines; ovipositor greatly reduced, certainly function- 

 less; abdomen of male without ventral sensory areas and without strong, 

 chitinous projections on apical segments. 



Type,: Merothrips morgani, new species. 

 In the weakened, pale cuticula, reduced organs of vision, 

 enlarged femora, and functionless ovipositor, the whole in- 

 sect shows a remarkable adaptation to life under bark and in 

 other similarly secluded places a habit until now wholly un- 

 known among the Thripidse. The affinities of such an anoma- 

 lous genus may be thought open to speculation, but, in our 

 present arrangement of the genera of this, family, it seems to 

 take a natural position just after Chirothrips. The ancestors 

 of this form were almost certainly Chirothrips-\\\i Thripi- 

 dse which, originally passing only the winter under bark, became 

 gradually adapted to that method of life as a fixed habit, 

 through finding there suitable food and adequate protection, 

 both from enemies and unfavorable climatic conditions. The 

 loss of the ovipositor is easily explained, for, as in the Tubu- 

 lifera, there is no need to hide the eggs in plant parenchyma 

 to avoid their being injured, because under bark may be found 

 safe hiding places in plenty. 



Merothrips morgani, new species. (PI. V, figs. 1-3.) 



Female. Length about 0.8 mm. Color pale grayish yellow, gray, or 

 brown, with head, legs (especially the anterior pair), and first two antennal 

 segments suffused with yellow. 



