MAEINE INVEETEBRATA OF GRAND MANAN. 



The Island of Grand Manan, the natural history of which this paper is intended 

 to illustrate, is perhaps but little known, geographically, to many who may be 

 readers of this account. It may not be out of place, therefore, to make some 

 remarks on its position. It is more properly an archipelago than an island. The 

 smaller members of the group lie to the east of the largest, which is twenty miles 

 in length, with a general trend north-east and south-west, having an average 

 breadth of nine or ten miles. It lies at the mouth of the Bay of Fundy, about 

 ten miles from the western shore at Campo-bello and Eastport, and thirty 

 from the Nova Scotia shore. It is surrounded on all sides by deep water (a 

 hundred fathoms or more), as might be judged from the character of the shores, 

 which are rocky and precipitous, especially on the western side, where cliffs of a 

 basaltic structure rise perpendicularly to a height of several hundred feet. On 

 the south-eastern side, where fhere are numerous islands, the shores are low and 

 shelving, composed of Mica^slate having a dip of about 70°. The passages 

 between these islands, worn out by the tides which rush with great velocity 

 through them, are generally very shallow, while a short distance seaward the 

 water becomes as deep as on the western side. 



The following paper is intended as a compend of observations made on the 

 marine fauna of this region, during three months' residence in the summer of 

 1852; and also as a catalogue, which it is hoped will prove nearly complete, of 

 the marine invertebrates found on its shores and in the adjacent waters. 



In preparing local faunas, it is desirable that the area included should be as 

 narrowly circumscribed as the inclusion of the requisite variety of station will 

 allow. It is only by the comparison of the results of such examinations, made 

 at a series of joints along a coast, that an accurate knowledge can be obtained of 

 the distribution of marine animals, and of the effect of external circumstances on 

 their growth, habits, and economy. We can thus ascertain whether a species may 

 inhabit two distant localities without occurring in the intermediate space ; and if 

 so, what are the causes of this? Has it been there extirpated by geological 

 changes not affecting the other points ? If not, how was its transportation effected? 

 Or, was it originally created in both the distant points? These, and many other 

 questions of the same nature, may be answered in respect to species whose distri- 

 bution is thus perfectly known. Such investigations will also throw much light. 

 on the distinctions of species, which cannot now be derived from their geographical 

 distribution, on account of the loose and general manner in which it is usually 

 recorded. And every practical naturalist knows how much he is aided in defining 

 species, by seeing them in the beauty of life, in their natural condition and asso- 

 ciations. So extended a series of observations will, however, require a great 

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