November, 1922 
The Queensland Naturalist. Ill 
A TELESCOPING ROTIFER. 
By W. R. COLLEDGE. 
Iii the early Spring, near the bottom of the pool, is 
frequently found the curious rotifer Neptunius . Exter- 
nally, it resembles the common R vulgaris , but on closer 
examination the lower portion of the body is seen to 
consist of six tubular joints telescoping into each other. 
Usually they are carried closed up in the interior of the 
Rotifer Actmurus Neptuni us 
Magnified 66 times. 
Closed. Extended. 
body, the end of the innermost, with its three outwardly 
curved toes forming the tail. Too small to be seen without 
the aid of a microscope, it possesses in addition to a com- 
plete muscular and nervous system, also some form of 
hydraulic pump under most efficient control. It swims 
freely by using the cilia on the head, but the movement 
is arrested at any time by touching an object with the 
tip of one of the toes. A spot of mucus, insoluble in water, 
exudes, and acts as an elastic anchor. It spins round 
as on a pivot, searching the space for food, then, pushing 
cut a joint, and so acquiring more length, it searches the 
larger area, and so joint after joint is pushed out until 
it is three times the length it appeared to be originally. 
A sudden jerk breaks the adhesion, the joints close up, 
and it sails away to pastures new. 
