A contribution to our knowledge of the Stylopidae. 263 
tremity was the part protruded, and that the anterior portion de- 
generated completely. Nassonow (1892) has accepted von SIEBOLD’s 
view and shown that the nervous system of the female bears out this 
conclusion, for the supra- and infra-oesophageal ganglia can be distin- 
guished without difficulty in sections of the protruded portion. This 
I have verified in many of my sections. Such sections also show from 
the position of the first ganglion that the external surface of the 
head is morphologically the ventral one. The escape of the young 
can hardly be considered more remarkable in occurring from the head 
than from the anal extremity, for the brood canal extends along almost 
the entire length of the body, and is really nothing more than the 
space between the animal and its partially cast-off chitinous envelope. 
Systematic Position. 
This is such a hackneyed subject that I feel disinclined to add 
to the already numerous opinions of authors. At present it does not 
seem that embryology is destined to bring to light any affinities be- 
tween the Stylopidae and any of the families of the Coleoptera. But 
as the embryology of the Rhipiphoridae has scarcely been studied, I 
do not wish to intimate that it may not throw considerable light 
upon the relationship of these insects with the Stylopidae when better 
known. The strange Rhipiphorid genus Rhiphidius, which lives as a 
parasite of the cockroach (Eetobia germanica) in Europe and India 
resembles the female of the Stylopidae in never leaving the body of 
its host. It has, however, well developed antennae and mouth-parts 
in the female and may prove to be utterly different from the Séylo- 
pidae, although it is quite possible on the other hand that it may 
very closely resemble them and serve to connect them with the Rhipi- 
phoridae. Unfortunately this form is extremely rare and neither the 
condition of its reproductive organs nor its life history are known. 
Differences between the Stylopidae and Coleoptera are so great 
that I can at present see no valid reason for including them in the 
same order. | 
Summary. 
The behavior of stylopized wasps towards their parasites is usually 
friendly, although it is probable that the males are attacked by the 
wasps whenever they attempt to copulate with the females. Their 
distribution and occurrence are erratic; due apparently to the fact 
that as triungulins they do not readily become transferred from one 
