DESOElPTION OP PLATE 0. 
99 
DESCRIPTION OF PLATE C. 
Fig. 1 .- — a a, antennae with its nerves running to the 
plexus in the middle of the head ; e eyes ; o o, ocelli ; 
r, rostrum ; /, plexus of nerves in communication with 
the above organs ; nervous filament in the leg pro- 
duced to the tarsus ; mm^ masses of muscle which act 
on the pterigostia or wing-insertions w w. The 
muscular fasciculi may be well seen in the thorax of 
the winged Si^phono^hora rosarum after treatment with 
acetic acid or dilute alcohol : g, oesophagus or gullet ; 
&5 stomach ; d, the long and simple intestinal canal 
filled with numerous pulpy pellets. In some species 
the gullet walls are roughened by the presence of 
small intestinal folds or open pockets : Ji, colon partly 
filled with fsecal matter ; anus ; cauda or tail ; 
c, cornicles or nectaries ; s ss^ stomata from which the 
tufts of trachese proceed ; portion of a large air tube 
which takes a zig-zag direction down the back. To 
this the ends of the finer trachese anastomose. 
The drawing probably does not show the exact 
curve taken during life by the alimentary canal. In 
some cases it appears to form a double loop, but the 
folds are difficult to determine. 
These details are from Siplionophora pelargonii^ 
dissected in syrup. 
Fig. 2. — Head and part of the thorax of Siphono- 
phora dirhoda, showing the lobe-like masses of salivary 
glands. Small green vascular fibres may be traced 
also in the neighbourhood of the rostrum of Siphom^ 
phora rosarum, which may be referred to the salivary 
apparatus. 
Fig. 3.— Head of Siphonophora ruhi with similar 
masses of salivary vessels. 
Fig. 4. — Portion of the same drawn under a 
immersion lens. The looped form of the ducts is 
