June, 1903.] 
Society of the Sigma Xi. 
45 1 
Jassidte, all of which have active jumping habits. Hence, this 
peculiar chela may have been developed for the special purpose of 
holding to the host larva while an egg is being deposited. 
Explanation of Plate 20. 
Fig. j — Nymph of Onnenisseptentrionalis, showing the sack in which the 
larva of Dryinus ormenidis lives, protruding from beneath the right wing 
pads, X5. Fig. 2 — Cocoon of D. ormenidis ; a, the flatter portion of it ; b, 
the more convex portion which contains the pupa ; c, exuvia of nymph of 
O. septentrionalis ; d, the empty sack from which the Dry inus larva has 
escaped, X5. Fig. 3— Leaf upon which there are three cocoons; a and c, 
cocoons of D. ormenidis, surmounted by exuviae ; b, cocoon of Labeo typh- 
locvbte, surmounted by larval sack, natural size. Fig. 4-S — Dryinus ormeni- 
dis! Fig. 4 — Larva, x”io ; Fig. 5 — Ventral view of pupa, x 10 ; Fig. 6 — adult 
female, xio; Fig. 7— tarsus of fore leg; a, antennal brush, or comb on the 
first segment of tarsus ; b, tibial spur which holds the antenna against the 
comb while being cleaned ; c. peculiarly modified 5th tarsal segment, x 37. 
Fig. s — Tarsus partly flexed at base to show how the spur conies into apposi- 
tion and works with the antennal comb, x 37. 
Explanation ok Plate 21. 
Fig. 1 — Adult male of Labeo typhlocybae, x 10. Fig. 1 a — Forewing of L. 
typlilocybae, showing venation as it appeared shortly after transformation, 
x 10. F'ig. 2 — Ventral view of pupa of L. tvphlocybae, x 10. Figs. 3-10 — 
Cheiloneurus swezeyi : Figs. 3-4— Adult female, x 10 ; Figs. 5-6 — ventral and 
dorsal views of pupa, x 10 ; Fig. 7— antenna, x 50 ; Fig. S — fore leg, at a, 
antennal comb, X50 ; Figs. 9-10— tibia and tarsus of second and third legs, 
b, movable spur, x 50 ; Fig 11 — female Gonatopus bicolor, x 10. Fig. 12 — 
male Labeo longitarsis, x 10. Fig. 13— nymph of Liburnia lutulenta with 
parasitic larva in sack on its abdomen, x 10. Fig. 14 — fore-tarsus of female 
Gonatopus bicolor, x 40. 
THE SOCIETY OF THE SIGMA XI. 
Among Greek letter societies the one which is of especial 
interest to students of science is the Society of the Sigma XI. 
Its badge is now seen so frequently at meetings of scientific men 
that it is well to know exactly what it stands for. In 1886 at 
Cornell University the first chapter was founded and the initial 
letters of the phrase meaning “ companions in zealous research ” 
made the name of the society. Since this beginning it has grown 
especially during the last few years until now nearly ever}- large 
university in the country has a chapter, the most recent additions 
being Chicago and Michigan. 
It is an honor society open to men and women who have 
distinguished themselves in scientific or technical work. By the 
constitution two standards are set up ; one relating to the eligi- 
bility of members of a college or university faculty and to alumni 
and one to students in the fourth year class. The first standard 
calls for an actual contribution to science and the second for such 
scholarship and success in scientific or technical studies as to give 
promise of ability to carry on research work. 
