#11 t|e ^rtatljiitg Jqitatit f aitit. 
By W. J. fuller, F.C.S. 
rriHE object of the following Paper is to lay before the Society 
X one or two peculiarities wLich I have noticed in the breath- 
ing apparatus of some aquatic larvse. The first to be considered 
are the lAhellulidcR, and then a short sketch of Corethra and 
Chironomus will follow. 
The larvae of the Libellulidce are very interesting creatures, 
though they are sluggish in their movements ; some {e. g. 
jEschna and Agrion) perch all day on aquatic plants ; others 
(e. g. Lihellula) bury themselves in the mud up to their eyes 
and stay perfectly motionless till some unsuspecting water 
shrimp or Daphne comes swimming near them, when the 
labium (which is formed to work like a man’s arm, the shoulder 
being attached to the chin, and the hand extending over the 
lower part of the face when at rest) is suddenly extended, and 
the unfortunate shrimp is caught in the hand-like extremity and 
conveyed to the mouth. 
The larvse can, however, move moderately fast if frightened, 
and they do this by drawing water into a sac, which is situated 
in the caudal extremity of the abdomen, and expelling it by 
contraction of the abdominal rings, thereby propelling themselves 
an inch or two forward, and repeating this, they progress with a 
jerky movement. That this is 'really the mode of progression 
may be seen by placing them in a glass of water with a little 
sand at the bottom, when the effect of the jet from the tail is 
B 
