6 
Siphonophora Rosarum 
The tail or cauda is, as Buckton says, quite inconspicuous, and is 
scarcely visible from the dorsal surface. It is completely covered with 
short stumpy hairs, which also surround the anal and reproductive 
apertures. 
Fig. 7. Lateral view of eye and ocellus. (x 108.) 
ant. = antenna, e. =eye. oc. = ocellus. 
Fig. 8. A cornicle or nectary. ( x 100.) 
cor. — cornicle, toms. = controlling muscle. 
The Alimentary Canal. 
The alimentary canal of Aphides in general has been figured from 
time to time by various authors, among whom may be mentioned 
Dufour (1833), Buckton (1875—82), Witlaczil (1882), and others. 
Witlaczil’s figure of the alimentary canal of Aphis pelargonii agrees 
in many points with the results I have obtained. 
The alimentary canal presents many remarkable features, the most 
striking of which is the complete absence of pyloric caeca or malpighian 
tubules. Dufour, among the earliest investigators of this part of the 
anatomy, expresses his astonishment thus:— 
“ L’appareil digestif des Pucerons presente une exception fort 
remarquable, unique.; c’est l’absence absolue des vaisseaux 
hepatiques.” 
The alimentary canal (Text Figs. 9 and 10) commences at the oral 
aperture which is situated on the lower posterior side of the head, and 
is so placed that it lies in close connection with the groove which 
traverses the whole length of the upper surface of the proboscis or beak, 
