378 REPORr>i^OM.\IISSIO]N"ER OF FISH AND FISHERIES. 



Lamellihranchs. 



Page 



riiolas trnucata 372 



Tagelns gibbus 373 * 



Mjn areuaria 372 



Muliuia lateralis 373 



Macoma fusca 372 



Cumiugia telliuoides 374 



Augnlus teuer 372 



Petricola plioladiformis 372 



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Venus mercenaria 372 



Kellia plaunlata 374 



Argiua pexata 372 



My tiliis edulis 372 



Modiola plicatula 374 



M. hamatus 374 



Pecten irradiaus 374 



Osti\Ta Yirgiuiana 374 



Ascidians. 



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Molgiila MauLatteDsis 375 ! Botnilus Goiildii 375 



EADIATA. 



EcMnoderms. 



Page. 

 Tbyoue Briareus 37G 



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 Asterias areuicola ... 376 



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 Hydractinia polycliua 37G 



Acaleiihs. 



Halecium gracile 376 



Page. 



t5' 



II. 4. — ANIMALS INHABITINa THE PILES AND TIMBERS OF WHARVES AND 

 BRIDGES, BOTTOMS OF VESSELS, BUOYS, AND OTHER SUBMERGED 

 WOOD-WORK. 



In tbese 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 

 w\}on submerged wood. Some of these, like the Teredo^ for example, are 

 of so great imi)ortance, 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 jiarticular 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 alg;e. afford congenial homes to a considerable 

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

 shores and in tide-pools. Beneath the wharves, where the ])iles are con- 



