REPORT OF COMMISSIONER OF FISH AND FISHERIES. [378] 

 Lainellibranclis. 



Page. 



Pkolas truncata 372 



Tagelus gibbus 373 



Mya arenaria 372 



Mulinia lateralis 373 



Macoma fusca 372 



Cumingia telliuoides 374 



Angulus tener 372 



Petricola pholadiformis 372 



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Yenus mercenaria 372 



Kellia plauulata 374 



Argina pexata 372 



Mytilus edulis 372 



Modiola plicatula ; 374 



M. hamatus 374 



Pecten irradiaiis . , 374 



Ostrrea Yirginiaua . 374 



Ascidians. 



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Molgula Mauhattensis 37o Botryllus Gouldii 375 



KADI AT A. 



Ecliinoclcrms. 



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Thyoiie Briareus 376 | Asterias arenicola 376 



Acalephs. 



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Hydractinia polyclina 376 Halecium gracile 376 



II. 4. ANIMALS INHABITING- THE PILES AND TIMBERS OF WHARVES AND 

 BRIDGES, BOTTOMS OF VESSELS, BUOYS, AND OTHER SUBMERGED 

 WOOD-WORK. 



In these situations a large number of species may be found, but the 

 majority of them are not peculiar to such stations. There are, however, 

 quite a number of species that are nearly always found under these cir 

 cumstances, and others are directly dependent for their very existence 

 upon submerged wood. Some of these, like the Teredo, for example, are 

 of so great importance, owing to the injuries which they do to valuable 

 property, that it seems desirable to make a special division for the 

 animals ordinarily found in connection with wood-work of various kinds, 

 whether injurious or not. 



On the piles of wharves and bridges various kinds of sea-weeds often 

 grow in abundance, each species having a particular zone to which it is 

 limited ; but as these plants require light, they are found almost exclu 

 sively upon the outer rows of piles and timber, and are most abundant on 

 the outer side of the piles and on the southern exposures, where they get 

 the most sunlight. These alga &amp;lt; afford congenial homes to a considerable 

 number of animals, most of which occur also among algre on the rocky 

 shores and in tide-pools. Beneath the wharves, where the piles are con- 



