THE THYSANOPTERA OF CALIFORNIA. 57 



Prothorax noticeably larger than head, without conspicuous mark- 

 ings; anterior angles straight, posterior broadly rounded. A large 

 spine on each anterior angle and a second on anterior margin on either 

 side about half way between the first spine and the median line; three 

 large spines on posterior margin on either side about equidistant apart, 

 the outer one being the conspicuous spine on the posterior angle; other 

 spines extremely small. Mesothorax widest, sides arched, evenl}^ 

 united with metathorax; sides of metathorax almost straight, but 

 widening toward the abdomen. Thorax slightly orange colored. 

 Legs medium, brown, except fore tibite and all tarsi, which are light 

 brown. Hind tibite and tarsi armed each with a sharp spine. Wings 

 present, reaching to tip of abdomen; gray-brown, eacli with a small, 

 white, transparent area about one-fifth the wing's length from its 

 base. Two longitudinal veins, fore vein extending from base to near 

 tip, hind vein appears close after the white area and fades before the 

 end. Fore margin of wing and longitudinal veins set regularl}^ with 

 short, sharp-pointed brown spines, twenty-three on fore margin, 

 eighteen on fore vein, twelve on hind vein. 



Abdomen with prominent spines only on last few segments; a weak 

 comb-like arrangement of spines on the posterior margin of segment 8. 



Described from one female. 



Fo.od plo n t: Grass . 



Hah i tat: Berkeley, Cal. 



(14) Euthrips occidentalis Pergande, and (15) Euthrips tritici Fitch. 



For descriptions of these species see Hinds's Monograph of the 

 Thysanoptera of North America, pages 15!^ and I-IS, respectively.'* 



6. Genus PARTHENOTHRIPS Uzel. 



(16) Parthenothrips dracaense Heeger. 



For description see Hinds's Monograph, page 176. Specimens taken 

 from draca^na in greenhouse in San Francisco, by Mr. E. M. Ehrhorn. 



7. Genus THRIPS Linnaeus. 



(17) Thrips madronii, new species. (PI. IV, figs. 34-36.) 

 Meaxui'eniciits: Head, length 0.11 mm., width 0.15 mm.; prothorax, 



length 0.13 mm., width 0.20 mm.; mesothorax, width 0.33 mm.; abdo- 

 men, width 0.33 mm.; total body, length 1.25 mm. Antennte: 1, 27jw; 

 2, 39yu; 3, 60/<; 4, 54yu; 5, 45yu; 6, 54//; 7, 21yu; total, 0.3 mm. Colo7' 



«The writer lias taken specimens of these two species of Euthrips {occidentalis 

 and tritici) from the most of our wild and cultivated flowers. They are commonly 

 found together. The variations in size, color, and in the relative lengths of seg- 

 ments of the antennae (in each of the two species) are so great that the writer has 

 been unable to draw a sharp line of distinction between them. 



