10 



Bryozoan Cristadella Mucedo only twice within the 

 two years I have been examining this drink-water. The 

 single ones are fastened together in three longitudinal - 

 rayed lines, with a general sucker on the lower part of 

 the body, which body moves but very slowly in the sedi- 

 ment. Of all Bryozoans the Cristadella mucedo is the 

 only one having the facility of moving. Allman, of 

 London, calls this Bryozoan-family the Phyllacto- 

 l^emata, on account of the tongue-like cover placed 

 over the ciliated mouth. The whole animalcule looks 

 like a very little transparent sponge. 



Now and then we find a worm possessing character- 

 istics absolutely " sui generis " of a milky color, whose 

 stomach {alimentary canal) branches like a tree, whose 

 mouth is placed on the belly, having two eyes on the 

 head ; this is called Dendrocoelum Lacteum, or Plan- 

 aria lactea. (Plate III, Fig. VII.) Its body is very 

 soft, and surrounded with vibrating cilia, the movements 

 are snail-like. Its systematical position in Zoology is in 

 the order Turbellaria — Worms. 



Three other creatures, belonging to the worms (Rota- 

 toria) called Rotifer, Hydatina and Stephanops, are 

 of frequent occurrence. They are very small organisms* 

 but larger than the largest Infusorials, possessed of a 

 mouth, jaws, intestine, chitinous skeleton, and increase 

 rapidly by the production of eggs. 



Individuals with separate sexuality. 



Of the Worm order, Nematoda {roundworms) occurs 

 Anguillula (1,0 to 2,0 Mm. long), sl worm occurring 

 in almost all fresh waters in the sediment 3 which have a 

 great resemblance to the very well known analogue, or- 

 ganized Trichina spiralis. Of the class Crustacea are 

 found three orders, each represented by a few species. 

 The predominating Cyclops quadricornis belongs to 

 the order Copepoda, has jumping (satiating) move- 



