[465] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 171 



Annelids. 



Page. 



Page. 



Nereis virens 



!N. limbata 



Rhynchobolus Americanus. 

 E. dibranchiatus 



463 

 463 

 463 I 

 Spio robustus ............. 345 j 



Scolecolepis yiridis ........ 463 \ 



S. tenuis . . 345 



463 | Clymenella torquata 343 



Cisteuides Gouldii ... 323 



Sabellaria vulgaris 321 



Lumbriculus tenuis 

 Clitellio irroratus 

 Halodrillus littoralis 



Meckelia ingens 



Nemerteans. 



Page, i 



349 Meckelia rosea 



MOLLUSCA. 



Gastropods. 



463 



463 

 463 



Page. 

 350 



Page. | 



llyanassa obsoleta 463 \ 



Tritia trivittata 463 



Eupleura caudata 371 



Page. 



Odostomia trifida 307 



Bittiam nigrum 463 



Crepidula convexa 463 



Astyris lunata 463 I Melampus bidentatus 



Lamellibranclis. 



463 



Page. 



Mya arenaria 463 



Macoraa fusca 463 



Angulus tener 358 



Tottenia gemma 359 



Venus mercenaria. . 463 



Page. 



Laevicardium Mortoni 358 



Solenomya velum 360 



My tilus edulis 307 



Modiola plicatula 307 



Pecten irradians . . 361 



III. 2. ANIMALS INHABITING- THE MUDDY SHORES AND BOTTOMS or 



BRACKISH WATERS. 



The bottoms of the sheltered estuaries, ponds, and harbors, are almost 

 invariably muddy, throughout the greater part of their extent, from low- 

 water mark to their greatest depths, or, in other words, wherever the 

 waves do not act with considerable force. The shores between tides are 

 also muddy in the more protected localities, where the waves do not 

 have sufficient power to remove the fine sediments. The upper and nar 

 rower parts of nearly all the estuaries in this region are, on this account, 

 muddy, for the rapidity of the tide is seldom sufficient to entirely re 

 move the fine sediments brought down by the streams. 



A large part of the muddy bottoms is generally covered in summer by 

 extensive patches of eel-grass. Over other portions large beds of oys- 

 13 v 



