18 
affinity with the TrichogramminsB. He seems, however, to have had 
another and true tetrastichine form before him which he considered 
identical with Pteroptrix. In his Nachtrag he changes the name 
Pteroptrix (which, by the way, he spells Pterothrix, as amended by 
Nees)to Gyrolasia, on account of the preoccupation of the former name 
by a genus of composite plants. On account of the probability that he 
had before him a true tetrastichine, we can retain the genus Gyrolasia 
in the Tetrastichiinc, and since we have what is, with little doubt, 
Westwood's form, which, upon close study, proves to be an aphelinine 
in spite of its 4 jointed tarsi. Westwood's original name maybe revived 
under its original form, Foerster's reasons for changing the name being 
insufficient. The doctrine that "once a synonym always a synonym" 
will hardly hold here, if we are correct in our supposition that Foerster 
bad a different form 
before him. 
The main characters 
by which the genus 
may be distinguished 
are as follows ■ 
Antennae 8- jointed, 
pedicel b r o a d and 
very short, joints 1 
and 2 of flagellum 
very short and nar- 
row, as in Aphelinus, 
third, fourth, fifth, and 
sixth joints forming 
the club, third some- 
times distinct from 
the club. Mesoscutar 
parapsides short, reaching only to teguhc; scutellum transversely 
elliptical; marginal vein of forewings long, much longer than stigmal. 
Wings with rather long marginal cilia. Abdomen rounded, perfectly 
sessile ; middle tibial spurs short ; tarsi 4- jointed ; first, second, and third 
joints subequal in length, fourth joint considerably longer. This last 
is an unusual character and would indicate the possible coalescence of 
the normal fourth and fifth joints. 
Fin. 4. — PUroptritt fiavimedia (Howard): male; female genitalia a4 
right, enlarged middle tarsus al left, antenna above— greatly 
enlarged (original). 
Pteroptrix flavimedia (Howard) (fig. 4). 
(hi vol a sin flavimedia Howard. Report of the Entomologist, Annual Report 
Department Agriculture, 1880, p. 369, PI. XXIV, fig. 5. 
Male and female. — Length, 0.7 mm.; expanse, 1.9 mm.; greatest 
width of fore wing, 0.32 mm. Antennae short, sparsely covered with 
short hairs; scape slender; pedicel broader, twice as long as broad; 
funicle 3-joiuted, joint 1 very minute (a true ring joint), joint 2 nar- 
