110 Proceedings of the Biological Society of Washington. 



about 4.7 times as long as wide; 4 about 0.8 the length of 3; 5-9 together 

 very slightly longer than 3, the last four segments together nearly as long 

 as 5, 9 shorter than 8; sensory area on ventral surface of segment 5 cir- 

 cular. Maxillary palpi three-segmented; labial palpi four-segmented. 



Prothorax about two-thirds as long as greatest width, distinctly 

 broadened behind. Mesothorax a little less than 1.4 times as broad as 

 prothorax, anterior angles broadly rounded ; mesoscutum closely trans- 

 versely striate. Metathorax with sides roundly converging posteriorly; 

 metascutum reticulate. Wings of fore pair moderately slender (about 

 seven times as long as width at middle), slightly narrower in basal third; 

 venation normal ; basal fifth and apex white, remainder dark brown- 

 gray, except a white spot occupying costal half of middle fifth ; hind 

 wings pale gray, darker in second and fourth fifths. Legs rather short 

 and stout. 



Abdomen stout, of normal structure. 



Measurements of holotype: Length L51 mm. ; head, length 0.149 mm., 

 width 0.187 mm.; prothorax, length 0.144 mm., width 0.229 mm.; 

 pterothorax, width 0.312 mm. ; fore wing, length 0.960 mm., width near 

 base 0.122 mm., at middle 0.132 mm. ; abdomen, width 0.377 mm. 



Antennal segments: 12 3 4 



Length (m) 36 53 113 92 



Width (m) 36 28 24 24 

 Total length of antenna, 0.411 mm. 



Described from a homogeneous series of 7 females bearing the following 

 data: Maryland: Great Falls (type locality). May 23, 1915 (1 female), 

 on foliage of Robinia pseudo-acacia L. [J. D. Hood] ; Beltsville, May 2, 

 1915 (1 female), on foliage [W. L. McAtee]. Virginia: Vienna, May 3, 

 1913 (3 females), on foliage of pear [R. A. Cushman] ; Rockfish, June 6, 

 1915 (1 female), in flower of Erigeron annuus L. [L. 0. Jackson]. Nevj 

 York: July 10 (1 female), on foliage of pear [H. Glasgow]. 



The color of the fore wings and antennae and the proportionate lengths 

 of the antennal segments separate this species very readily from its North 

 American congeners. It is apparently very close to the European ^. 

 Melaleuca Haliday, which can not now be secured for comparison. 



Heterothrips azaleas sp. nov. 

 (PI. Ill, Fig. 1.) 



Female (macropterous). — Length about 1.26 mm. Color dark blackish 

 brown, with tarsi, distal ends of tibife, and third antennal segment pale 

 grayish yellow ; fore wings dark brownish gray except for a white trans- 

 verse subbasal band. 



Head about 1.4 times as wide as median dorsal length, distinctly 

 shorter than prothorax, widest behind eyes, thence narrowing abruptly 

 to eyes and tapering slightly to base; surface with a few minute spines, 

 impressed and transversely rugose in front of anterior ocellus, smooth 

 between ocelli, and with four or five anastomozing striae on occiput; 



