
Notes on the derivation of winged insects through several lines etc. 269 
Patria: Westjava, Umgebung von Buitenzorg. Type in der Kollection 
des Herrn Prof. Dr. L. Courvoisier in Basel. 
Gerydus courvoisieri phradimon subsp. nova. 
JS. Das weiße Gebiet der Vorderflügel noch ausgedehnter als bei 
der Java-Vicariante, ausgezeichnet durch einen sehr langen, zwischen 
der hinteren und der Submediana sich hinziehenden weißen Strich. 
Unterseits mit verminderter Weißfleckung, welche nach vorn nicht über 
die vordere Mediana hinausgeht. j 
* dem Gerydus learchus philippus Stdgr. 2 genähert, nur die 
weiße Binde ist etwas länglicher, wodurch sich ein Anklang an gewisse 
“2 von @. biggsi Dist. ergibt. Die Hinterflügel schärfer gewinkelt als 
bei philippus Stdgr. und von diesem ohne weiteres zu unterscheiden 
durch das Fehlen der graugelben Beschuppung, welche das Discalfeld 
aller Formen von learchus verdunkelt. 
Patria: Nord-Borneo, Waterstradt, leg., 2 West-Borneo, Sintang. 
März 1910 (Dr. Martin leg.). 
Es ist ziemlich sicher, daß sich @. courvoiseri auch noch auf 
Sumatra und der malayischen Halbinsel vorfindet. | 
Notes on the derivation of winged insects through several 
lines of descent. 
G. C.- Crampton, Ph. D.* 
The erroneous idea that all winged insects are the descendents of 
a single type of winged insect, which in turn was derived from some 
on type of primitively wingless insect, has proven a serious stumbling 
block to further progress in attempting to derive the Pterygota from 
ancestors resembling the Apterygota. It is very difficult to understand 
how such an idea could have arisen, for the evidence gained from 
a comperative anatomical study of the more primitive representatives 
of the Pterygota and Apterygota clearly points, not to one, but to 
several lines to descent, in passing from the one group to the other 
It is perhaps superfluous to add, that in speaking of the descent of 
the apterygote insects from apterygote forms, it is not implied that 
recent Pterygota are the descendenis of recent Apterygota, but merely 
that the ancestors of both groups were very intimately related, or 
sprang from a common stock. 
The marked similarity of structure found in insects belonging 
to the apterygote group Myrientomata and those belonging to the 
pterygote group Platyptera (i. e. the Plecoptera and Embioidea — but 
not the Isoptera and Corrodentia, which are included in the group 
Platyptera by some systematists) would indicate a community of descent 
in these two groups. For the sake of convenience, this line of descent 
may be spoken of as the Myriento-Platyptera line, and the insects 
therein ineluded may be referred to as the Myriento-Platyptera group. 
The great similarity in structure between the apterygote insects 
called Dicellura (the Japyx-like forms) and insects of the pterygote 
order Dermaptera, clearly points to the Dicelluro-Dermaptera group as 
representing another line of descent from the Apterygota to the Ptery- 
*) Contribution from the Entomological Laboratory of the Massachusetts 
Agricultural College, Amherst, Mass. 
