144 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



thorax broader than prothorax, sides nearly straight and converging pos- 

 teriorly. Wings apparently broad, of equal width throughout, slightly 

 clouded with brownish at middle. Legs of medium length, the fore femora 

 equal in length to head; fore tarsi armed with a short, stout tooth placed 

 at right angles to the tarsus. 



Abdomen large, broad, nearly 1.4 times as wide as prothorax, narrowing 

 roundly from about segment 4 to base of tube. Tube nearly as long as 

 head, slightly more than twice as long as basal width, and fully twice as 

 wide at base as at apex, slightly contracted at both base and apex. Lateral 

 bristles dilated and rather short, excepting for one pair each on segments 

 7 and 9 which are pointed and nearly as long as tube; terminal bristles 

 about equal in length to tube, brown. 



Measurements of holotype: Length 1.45 mm.; head, length 0.185 mm., 

 width 0.172 mm.; prothorax, length 0.168 mm., width (inclusive of coxse) 

 0.311 mm.; pterothorax, width 0.360 mm.; abdomen, width 0.420 mm.; 

 tube, length 0.172 mm., width at base 0.075 mm., at apex 0.035 mm. An- 

 tennal segments: 1, 30 M; 2, 52 M ; 3, 54 M; 4, 57 M; 5, 55 n; 6, 52 /r, 7, 51 M; 

 8, 30 n; total length of antenna, 0.38 mm.; width at segment 4, 0.034 mm. 



Female (forma brachyptera}. Apparently identical with the long 

 winged form, with the exception of the narrower pterothorax, which is 

 equal in width to prothorax. Abdominal segments 7 and 9 each with a pair 

 of long, pointed, lateral bristles, as described for the macropterous form. 



Described from two females taken by the writer near Bald- 

 win, Michigan, under loose bark on a freshly-cut poplar 

 stump, August 16 and 17, 1908. 



The remarkably long mouth cone and the armed fore tarsi 

 render this species very distinct. 



Genus PHLCEOTHRIPS Haliday. 



1836. Phlaothrips (sic!) Haliday, Ent. Mag., vol. in, p. 441. 



1895. Phloeothrips Uzel, Monogr. d. Ordn. Thys., p. 254. 



1899. Phloeothrips Reuter, Acta Soc. pro Fauna et Flora Fenniea, 

 vol. XVII, No. 2, p. 18. 



1902. Phlaothrips Hinds, Proc. U. S. Nat. Mus., vol. xxvi, p. 195. 



1912. Phlceothrips Jones, Tech. Ser. 23, pt. I, Bur. Ent., U. S. Dept. 



Agr., p. 21. (Gives key to North American species.) 

 The species coriaceus of Haliday must be considered the 

 type of this genus, for it is the only recognizable one known to 

 Haliday which has not been removed or reduced to synonomy. 

 Its North American components with the exception of zv'/- 

 tatus and maculatus form a homogeneous group remarkable 

 for the structure of the fore leg of the male, the femur having 

 two acute teeth on the inner side near the apex, between which 

 when the leg is flexed, fits a similar tibial tooth. This struc- 

 ture is constant in more than a dozen species known to me, 



