170 



SEA-SHORE LIFE 



etc.. 



larva with large rounded head, and lash-like tail. The larva usually 

 breaks through the egg membrane and swims through the water, 

 avoiding the light. Soon, however, it settles down, and becomes 

 fast to the bottom by means of the adhesive slime of its body. Often 

 it becomes fastened by the tail, but occasionally hj its head or some 

 other part of the body. The little creature then struggles vainly 

 to free itself for a time, but soon the tail becomes absorbed, the 

 nervous system degenerates and the animal becomes a Ciona, fixed 

 for life to one spot, and in its adult state no one would suppose 

 that it was in reality a vertebrate. 



Molgula inanhattensis, Fig. 119. This is found under stones, 

 below low tide level from Maine to the Carolinas. The body 

 is about one inch in diameter, rounded 

 in outline and usually covered more or 

 less with particles of sand and detritus. 

 In color it is dull olive green. Two 

 long tapering spouts project upward, the 

 uppermost being for the admission, and 

 tlie lower for the discharge of water 

 which passes through the gills. Alto- 

 gether the creature presents the appear- 

 ance of the water bottles made of skin, 

 such as are still used in the Orient, and 

 indeed the name aseidian signifies a 

 little water skin. The eggs are laid 

 a little before dajdoreak during the sum- 

 mer months, and the larvae develoiD in a 

 few hours into little tadpoles within the egg membrane, and finally 

 change into fixed tunicates without being set free from the egg 

 membrane. 



This species maj^ often be seen in tlie New York Aquarium, 

 where colonies of volunteer growth attach themselves to the rocky 

 linings of the tanks, and attain full growth in about six weeks. 



The Star-Spangled Jelly, fBotryllus gouldiij. This compound 

 aseidian ranges from New Jersey to Maine, and is very abundant 

 late in summer upon eel grass. It forms smooth, thick, gelatinoiis 

 expansions of various colors, such as gray-green, dull yellow, brown, 

 purple, or spotted with white. The whole surface appears as if 



Ft/;-, ng: MOLGOLA MANHAT- 

 TENSIS. Woods Holl, Mass. 



