478 REPORT OF COMMISSIONER OF FISH AND FISHERIES, 



Ascidians. 



Page. I Page. 



Cynthia partita 311 Molgiila Mauhatteusis 311 



Bryo.zoa. 



Page. ' Page. 



Bugula turrita 47G j Yesicularia dichotoma 470 



EscLarella variabilis 470 j Alcyouiclinm liirsutum 470 



Meinbranipora liueata 400 j Pedicelliua Americana 405 



RADIATA. 



Echinoderms. 



Page. 



Asterias areuicola 470 



AcaJejylis. 



Pase. 



Obelia gelatinosa 391 



O. diapbana 327 



O. pyriformis 390 



Pace. 



Halecium gracile 476 



Sertularia argentea 408 



Polyps. 



Page. I Page. 



Motridinm marginatiini 329 | Sagartia leucolena. . . .- 329 



PROTOZOA. 



Sponges. 



I'age. I Page. 



Tedania, species . 330 Eed branching sponge 470 



Halichondria, sp 330 



III. 4. — Animals inhabitingt 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, iu summer. This plant flourishes both on sandy and muddy 

 bottoms. During the ftiU 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 

 iu 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. 



