WORMS, MOSS-POLYPS, SPONGES, ETC. US 



There are few objects more interesting to watch 

 than a sponge in action, but with us, unfortunately, 

 the only native sponges of consequence are either 

 thinly-branched or encrusting forms, which scarcely 

 permit of observations being made upon their man- 

 ner of living. One of these is the Microscionia 

 proUfera, a rather scanty creeper on rocks and 

 shells, having when fresh a bright red color. 

 When full-grown it rises up into bunchy masses, 

 measuring six inches or more across, which may 

 be found scattered between the sedges of the sand 

 where the latter has been left exposed at low-water. 

 A much more delicate species, readily distinguished 

 by its long and slender ' oculated' branches, is the 

 Chalina arbuseula, whose habitat appears to extend 

 along the greater part of the Atlantic coast. 



The ' sea-bread' or ' sea-crackers,' rounded yel- 

 lowish masses of an exceedingly light texture, which 

 sometimes appear after a storm, are also skeletal 

 parts of sponges, but their closely-packed and re- 

 markably fine fibrous threads are composed princi- 

 pally of silica instead of horn, and thus approxi- 

 mate the type of the large and important group of 

 silicious sponges, to which the ' glass rope' and 

 ' Venus's flower-basket,' two of the most exquisite 

 of nature's objects, also belong. The sea-bread 

 (Suberites) has been dredged alive on the Massa- 

 chusetts coast, and it has therefore been conjec- 

 tured that its home must extend to that region. 



Much more insignificant than the preceding is 

 the form (Cliona) that attacks oyster- and clam- 

 shells, burrowing into their midst froni ^.ll direc; 



