476 MARINE INVERTEBRATES 



little rough ; color olive-green. The animal is often attached to rocks, 

 more frequently to eel-grass and seaweeds, and is sometimes so crowded 

 as to form large clusters. Found from Maine to North Carolina. 



M.. pellucida. Body nearly globular, about an inch in diameter, 

 smooth, clean, and translucent, the intestine showing through the test. 

 The two tubes are large, swollen at the base, and divergent. The animal 

 lives free in the sand, and is found from Massachusetts to North 

 Carolina. 



M. arenata. Body somewhat compressed laterally ; test thin and 

 covered completely with sand, which is closely adherent ; about three 

 quarters of an inch in diameter ; tubes short and wide apart. Found on 

 shelly and sandy bottoms of bays and sounds. 



GENUS Cynthia 



The animal is attached, the body coriaceous, and the orifices 

 four-lobed. Frequently associated in groups, the individuals 

 often differing in color. 



C. pyriformis. Body globular, or oblong when extended ; hard, 

 velvety, whitish surface, with pink cheeks; orifices on prominent pro- 

 tuberances on the upper surface. It lives in clear, deep water on rocks, 

 and is sometimes found at low- water mark on the northern New England 

 coast. Commonly called the sea-peach. (Plate LXXXV.) 



C. partita. Body oblong ; attached ; test horny and wrinkled : rusty- 

 brown ; apertures square, on prominent tubes marked with triangular 

 spots of Avhite and purple ; diameter one inch. Found on the piles of 

 wharves and on shelly bottoms in shallow water ; also on the under side 

 of stones when they are much flattened. 



C. carnea. Test low and flat, with a thin margin ; adherent by a very 

 broad base ; orifices small, square, slightly prominent ; red or flesh-color. 

 Found in deep water on stones and shells on the northern New England 

 coast. 



GENUS Boltenia 



Body more or less globular, on a long stem ; fixed ; orifices on 

 the side. 



U. clavata. Body long, wrinkled, leathery, on a long stalk, resem- 

 bling the flower of lady's-slipper (Cypripedium) ; two cross-shaped ori- 

 fices wide apart on the side ; yellowish in color ; attached to stones in 

 deep water, but sometimes washed ashore in storms. The stalks are 

 often covered with polyzoans and hydroids. (Plate LXXXV.) 



GENUS Ascidia 



Test gelatinous or cartilaginous ; attached; it grows in bunches 

 under stone? a* U>w-water mark. Sometimes it is variously col- 



