OF WASHINGTON. 299 



color shining black; head and thorax with greenish-blue reflections; 

 first, second, and third tarsal joints of all legs light yellowish. 



Male. Closely resembles female except in ordinary sexual differences 

 of antennae and abdomen. The head and thorax, however, have a bright 

 coppery or golden lustre. 



Of this species I have several male and female specimens reared 

 by Dr. B. G. Wilder, at James Island, S. C., from the cocoons 

 of Pimpla probably rufopectus within the egg-cocoons of 

 Epeira riparia, collected between March 21 and April 2. Also 

 four male specimens reared by Col. Nicholas Pike, at Brooklyn, 

 N. Y., 1880, from cocoon of Argiope riparia. Also many male 

 and female specimens reared, by Nathan Banks, at Sea Cliff, L. I., 

 from cocoons of the same spider. Also 1 1 male and female specimens 

 reared from a parasitized cocoon of an Epeirid collected at Wash 

 ington, D. C., by the writer. Also 5 male specimens reared from 

 cocoon of Epeira angulata infested by Pimpla aquilonia (?) 

 at Los Angeles, Cal., by Dr. A. Davidson. 



24. Tetrastichus banksii n. sp. 



Female. Length, 1.8 mm.; expanse, 3.1 mm.; greatest width of fore- 

 wing, 0.6 mm. Head and face with coarse punctures, which on the face 

 are arranged in four rows, one down each side of antennal groove and one 

 down the border of each eye ; mesonotum delicately longitudinally striate, 

 median furrow of mesonotum sharp and continuous with a faintly indi 

 cated median longitudinal furrow of the scutellum ; just mesiad of the 

 parapsidal furrows of the mesoscutum is a row of deep, large punctures, 

 which is continuous with the impressed lateral furrows of the scutellum; 

 these lateral scutellar furrows are continuous but seem composed of a 

 chain of punctures ; metascutum impressed in centre, the impression bear 

 ing a central papilla; meta-scutellum with a median longitudinal carina, 

 each side of which is a strongly rugose surface; pro-, meso-, and meta- 

 pleura closely punctate; abdomen smooth, shiny, concave above behind 

 the second segment through drying. General color black, with faint 

 greenish metallic reflections ; scape of antennae honey-yellow; mandibles 

 honey-yellow; all coxae and femora metallic, yellowish at joints; all tibiae 

 and tarsi light-brown with a darker shade above at base of tibiae. 



Described from three female specimens reared from egg-bag of 

 an Epeirid at Washington, D. C., by Nathan Banks, together 

 with seven specimens of No. 22 Holcopelte nitens. This 

 species is undoubtedly hyperparasitic, but whether it is primarily 

 parasitic upon Holcopelte, or upon some Ichneumonid, the Hol 

 copelte being then parasitic upon the Tetrastichus, is uncertain. 



25. Bseus americanus How. Insect Life, Vol. II, p. 270. 



Several male specimens reared from Epeirid eggs by Col. 

 Nicholas Pike, Brooklyn, N. Y. Also several males and one female 



