Vv 
Platyrhopalopsis. He believed the presence or absence of 
stridulatory organs to be a character of considerable systematic 
importance within the limits of a family, and what little he 
had observed in the Paussidae tended to confirm him in that 
belief. 
Rare Locust rrom Costa Rica.—Mr. O. E. Janson 
exhibited a fine and perfect specimen of Markia hystrix, 
Westw., a rare and remarkable locust received from Costa 
Rica, and directed attention to its evident protective char- 
acters in its curious cryptic coloration and the strongly spinose 
armature of the head, pronotum and legs. 
PIERINE BUTTERFLIES AND MIMETIC MOTHS MIGRATING 
FROM ONE VALLEY TO ANOTHER IN SELANGOR, F.M.S.—Prof. 
Poutton exhibited the whole of the captured examples of 
the morning and evening migrations at Bukit Kutu described 
in Proc. Ent. Soc. Lond., 1920, p. Ixiii. The eight additional 
specimens kindly sent by Mr. A. R. Sanperson.and Mr. 
T. R. Harvey, included another species of Delias and also 
of Dysphania. The complete series of nineteen was as 
follows :— 
Delias ninus Wall.—5 3g. Delias pyramus Wall.,--3 3, 
19. Delias aglaia L., £. parthenope Wall.,—1 3. Dysphania 
(Buschema) glaucescens Walk.,—4 3, 2 2. Dysphania (Eus- 
chema) militaris L., f. selangora Swinh.,— 1 3. Dysphania 
(Euschema) excubitor Moore, probably f. of subrepleta Walk. ,— 
1 3. Psaphis (Canerkes) camadeva Dbl.,—1 3: 
To this series a female of P. camadeva from Java had been 
added in order to show the perfection of the mimetic resem- 
blance to D. (£.) excubitor. One of the additional specimens 
now received thus verified the prediction ventured upon in 
the 1920 Proceedings (p. lxiv) :— 
“ Although during flight, the female P. camadeva would 
resemble D. glaucescens and, far more closely, D. militaris, it 
was probable that the better model D. subrepleta and perhaps 
other Dysphanias would be found to accompany the Delias 
in their migratory flights in Selangor.” 
And now excubitor (believed by Mr. L. B. Prout, who had 
kindly made this determination and verified the other 
species of Dysphania, to be a form of subrepleta) was shown 
