184 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [478] 



Ascidians. 



Page. 



Cynthia partita 



Page. 



Molffiila Manhattensis 311 



Bryozoa. 



Page. \ Page. 



Bugula turrita 476 | Vesicularia dichotoma . . . 



Escharella variabilis 476 Alcyonidiuin hirsutum . . 476 



Membranipora lineata 406 | Pedicellina Americana . . . 



RADIATA. 



Ecliinoderms. . 



Page. 



Asterias areuicola 



Acalephs. 



Page. 



Obelia gelatinosa 391 



O. diaphana 327 



Page. 



Halecium gracile 476 



Sertularia argentea 408 



O. pyriformis 



Polyps. 



Page. 

 Metridium marginatum 329 



Page. 



Sagartia leucolena. .... 329 



PROTOZOA. 



Sponges. 



Page. 



Tedania, species 330 . 



Eed branching sponge 476 



Halichondria, sp , 330 



III. 4. ANIMALS INHABITING EEL-GRASS IN BRACKISH WATERS. 



A large portion of the shallow parts of nearly all the harbors, estu- 

 aries, and ponds is occupied by a dense growth of eel-grass, Zostera 

 marina, in summer. This plant flourishes both on sandy and muddy 

 bottoms. During the fall and winter it is mostly torn up and drifted 

 away by storms, but in the spring a new crop starts up and grows very 

 rapidly, the narrow, ribbon-like leaves often becoming six feet or more 

 in length during the summer. 



These tracts of eel-grass are the favorite resorts of a considerable 

 number of animals, which seek these places either for food or conceal- 

 ment and shelter, or for both combined. Other species, including certain 

 hydroids, bryozoa, and ascidians, grow attached to the leaves of the 

 eel-grass. 



