amonjj; the most fascinating of minute creatures, when seen under favorable 

 conditions. They are usually found in quiet streams, lakes and ponds. Some 

 build little tubes on sticks and stones and, since they branch freely, the colony 

 soon takes on the appearance of a plant or a clinging vine. Others secrete 

 masses of jelly in the surface of which they remain embedded. One spectacular 

 form, Pectmatella, frequently builds up a spherical or oval colony a foot or 

 more in diameter, which cannot fail to excite the wonder and admiration of 

 the July or August observer. The full beauty of these colonies is seldom ap' 

 preciated, however, for the individual animals are very timid and retreat into 

 their protective sheaths until fully assured that all is w^ell. The colony should 

 be taken up carefully and put into a suitable glass container, so that it may 

 be covered with water and still be available for observation. One will find 

 it well worth the time and patience required to watch the surface of the colony 

 v.'ith a hand lens. Gradually each little animal in the group extends a pinkish 

 head and a lophophore or crown of waving tentacles, until the whole mass 

 appears to be a garden of delicate flowers. These fragile tentacles are for 

 the prosaic task of pulling in the microscopic organisms upon which the animals 

 feed and also serve the naturalist as an aid in identifying the various species. 



Like Sponges, the Bryozoa form little, well-protected globules of cells, 

 which carry over the winter. Instead of gemmules, these are called statoblasts. 

 Some forms bear a series of hooks which serve to anchor them until they are 

 ready to begin growth. In September, when the colonies usually disintegrate, 

 these statoblasts, looking superficially much like fig seeds, are often found in 

 rows or masses along the shores of our lakes and ponds. As in the sponges, 

 the reproductive bodies are often necessary for positive identification. 



OUTLINE OF CLASSIFICATION OF FRESHWATER MOSS-LIKE 

 AND JELLY-LIKE ANIMALS 



Phylum PORIFERA 



Sessile, aquatic animals with calcareous, siliceous or spongin fibers 

 supporting the body; numerous pores in the body wall open into a 

 central gastral chamber 

 Class NONCALCAREA 



Spicules siliceous or spongin 

 Order TETRAXONIDA 



Body spicules four-rayed or single, never three or six-rayed 

 Family HAPLOSCLERIDAE 



Long (body) spicules v^'ith both ends alike; small spicules not 

 greatly recurved on ends 



51 



