360 
not be one of the three species from Chile described below. I 
think that his species may be recognized with certainty from his 
drawing of the antenna (fig. 23) and especially from the branches 
mentioned; it has been captured in Eastern Massachusetts and at 
Philadelphia. 
2. P aur opus robustus n. sp. 
PI. II, fig. 2 a—2 f. 
Malerial. I have examined two adult specimens, one of which 
is a male, and the other, judging from the length of the claws on 
the last pair of legs, must certainly belong to the same sex (with- 
out damaging the specimen it was impossible to observe the copu- 
latory organs). They had been laid by Dr. Silvestri in a microsco- 
pical preparation together with a specimen of each of the two fol- 
lowing species. He had captured all four specimens at Temuco in 
Chile, determined them as P. Huxleyi Lubb. and published his dis- 
covery of this species in a note: Distribuzione geografica della 
Koenenia mirabilis Grassi ed altri Artropodi .. . (Zool. Anzeiger, 
XXIIB., Sept. 18. 1899, p. 369). But it must be emphasized 
that all three species are so closely allied to each other and to 
P. Huxleyi that a special study of the genus is necessary in order 
to detect and value the differences. 
I have preferred to give a shorter account of these species, 
essentially only pointing out the differences between them and P. 
Huxleyi. 
Head (fig. 2 a). The eyes are rather small and the distance 
between them one half longer than their length. — The hairs as 
to shape and length as in P. Huxleyi, only the sublateral hairs in 
the fourth row proportionately a little shorter. 
Antennæ (fig. 2 a). The upper one of the front hairs on the 
fourth joint is as long as the peduncle and much longer than the 
other. The upper branch is almost seven times longer than broad 
and almost longer than the peduncle; the flagellum is two and a 
third times longer than the branch. The lower branch as in P. 
