114 THE VICTORIAN NATURALIST. 



in aspect and equipment of the whole class. The order falls into 

 two great divisions. To the first belong those Rotifers which 

 possess no hard covering ; to the second those which are protected 

 by a chitinous shield. The first division is chiefly represented in 

 our pond by members of the family Notommatadre. These are 

 in many cases not easy to identify. The only one we shall 

 mention is the pretty little Furcularia longiseta — a form spe- 

 cially marked by the great length of its toes. The lateral aspect, 

 as seen in the engraving, shows a head well rounded, its front 

 covered with cilia, and a body having an arched dorsal and con- 

 cave ventral surface. One small joint represents the foot. The 

 toes, unusually long, are round and thick at the base, and taper 

 to a point, but their unique peculiarity is that one is a full third 

 longer than the other. The body of this Rotifer is partly coloured 

 yellow. A deep-set eye, attached to the brain, can be found by 

 careful focussing. A peculiarity of this creature is its power of 

 leaping, by which it sometimes vanishes from the field of view in 

 the twinkling of an eye. 



To our mind the true glory of the Ploima is found in the 

 second division — the Loricata. Their chitinous lorica is glassy, 

 often clear as crystal, sometimes ornamentally dotted or stippled. 

 It is usually outlined by graceful curves, and in many genera 

 runs out into points or spines at front or back. It consists of 

 dorsal and ventral or lateral plates variously joined together. A 

 species that is likely to show itself is Mastigocerca carinata. Its 

 lorica is shaped somewhat like a narrow barrel. Along the front 

 half of its dorsal surface a high arched ridge runs. This both 

 gives the Rotifer its name and makes it easy to identify. The 

 sides of the ridge are corrugated. The front of the head bears a 

 number of small tubercles, on which the cilia are set. A red 

 eye-spot is conspicuous, attached to the brain. The very long 

 trophi consist of three unequal rod-like portions. The animal's 

 one toe is very long, slender, and tapering, and has two or three 

 stylets at its base. There is usually bright green colour in the 

 stomach of this Rotifer, which is a very pleasing object, whether 

 seen gliding rapidly through the open water, or half-buried in 

 tangled algse, switching its long, inflexible toe from side to side. 

 But the beau ideal of an armoured Rotifer now swims by — 

 Dinocharis tetractis — sheathed from head to toe in a thick mail, 

 which rather suggests a crustacean shell, and presents no vulnerable 

 point. The lorica of the body, somewhat vase-like in shape, 

 viewed dorsally, is facetted, or divided into a number of small 

 areas, and prettily dotted. At the back it curves sharply to a 

 blunt point. Beneath this projects a foot of several shapely 

 joints, the first adorned with a pair of spurs. Two long toes 

 curving outwards complete the foot. This animal's rounded head 

 is protected by a separate piece of armour, which might be called 



