THE FLEXIBLE CREEPERS. 
485 
the form of two hanging lobes or ears, which are richly- 
clothed with vibrating cilia, and are powerful auxiliaries to 
swimming. Strong circular currents are formed around each 
ear, while the animal rests on its toes. As it swims, it is 
almost continually contracting the enormous head with a sort 
of spasmodic twitching, which brings the ear-lobes momen- 
tarily to point forward, and alternately, and almost as quickly, 
recovering itself. The conical lower parts of the body are also 
frequently contracted in various degrees, and drawn up to 
either side in the most irregular manner. These movements 
are made by the various muscle-bands and threads, which 
exist in great number, and are discerned to much advantage, 
owing to the crystalline clearness of the tissues. This brilliant 
transparency is highly characteristic of the tribe, and, com- 
bined with their elegant form and sprightly motions, makes 
them rank among the most charming representatives of the 
class. 
Just below the centre of the frontal crest there glows a very 
large oval eye of the richest ruby-crimson, through which the 
transmitted light is strongly refracted, as it would be by a 
globe of glass, showing that it is furnished with a true lens. 
This eye rests on a great mass of brain-substance, which when 
viewed from behind is seen to be much extended laterally. 
On each side of the eye are some large irregularly globose 
knobs of clear substance, from which descend two thick 
pieces, which meet at an angle near the middle of the body in 
the form of a massive V- From the summit of the frontal 
crest every now and then the animal protrudes two pairs of 
dark tooth-like points, curved towards each other, which open 
and close with a sudden snapping action, and are instantly 
withdrawn below the crest, where they can scarcely ever be 
discerned. For a long time I watched the recurrence of this 
motion, and marked the momentary protrusion of the jaw- 
teeth with the greatest interest, but with a most tantalizing 
impotence to solve their mystery. So totally unlike they 
seemed to the mouth apparatus in any other genus, that I 
longed for years to understand them. I saw by certain accom- 
panying twitchings in the globose heads of the V-shaped body, 
that the protruded points were intimately connected with them ; 
and I felt sure that if I could satisfactorily resolve them, I 
should acquire a flood of light on the as yet unintelligible 
structure of the mouth in the whole class. At length I 
thoroughly mastered it, and saw that it was by no means an 
abnormal apparatus, but essentially identical with the parts of 
what had been called the “ gizzard ” in the Rotifera generally. 
The two branches of the V are the mallei , or upper jaws, 
invested with thick masses of muscle: the hand, or “fork,” 
2 l 2 
