SPONGES OR PORIFERA 



29 



The Finger Sponge, (Clialina oeulata, Fig. 6), is dull red or 

 yellow in color and grows upon rocks or shells, forming finger- 

 shai^ed masses about six inches high. At intervals there are large 

 openings on the sides of the sponge which serve to allow the escape 

 of water from the interior. This sponge is common north of 

 Cape Cod at depths greater than fifteen feet. 



The Sulphur Sponge, (Suherites compaetaj, is a compact, heavy 

 sponge which grows on sandy bottoms o\Y the Long Island coast. 

 When living it is bright yellow, but soon 

 darkens into an ugly brown after death. 

 The surface of the sponge is smooth, rounded 

 and nodular. 



The Urn Sponge, ( Grant ia ciliata, Fig. 

 7 ), is common in tide pools on Long Island 

 where it grows in clusters of little urn-shaped 

 sponges, each urn being dull yellow, gray 

 or dral) in color, about one-half of an inch 

 high, and with a large opening edged with 

 spicules at the summit. It is found along 

 our coast northward to Greenland, and is 

 abundant on the northern coasts of Europe, 

 being drawn in through sieve-like oj^enings on the sides of the 

 sponge and forced out through the large terminal opening. 



Fig. 7/ URN SPONGE, 

 Woods Holl, Mass. 



Water is constantly 



