330 DEPARTMENT OF THE NAYAL SERVICE 



8 GEORGE V, A. 1918 

 GEOGRAPHIC DISTRIBUTION. 



For the consideration of the question of distribution, the waters of Eastern 

 Canada can be conveniently divided into three regions : (1) The Bay of Fundy and 

 its approaches, (2) the Gulf of St. Lawrence, (3) the east or southeast coast of I^ova 

 Scotia. 



In the Bay of Fundy the waters around the island of Grand Manan have been 

 much used as a collecting ground ever since Stimpson found a sufficient number of 

 species to make it worth while to write up " The Marine Invertebrates of Grand 

 Manan." Then, as now, it was recognized that on account of the exposed position and 

 the difference in tides, the channels between the numerous small islands must be con- 

 tinually supplied with enough food for countless forms of great variety. The archi- 

 pelago between Passamaquoddy bay and the Bay of Fundy proper provides a large area 

 where the conditions are somewhat similar although the salinity becomes noticeably 

 less in the inner waters. The whole area is suitable for hydroid growth. Even at the 

 mouth of the St. Croix river there is a sufficient interchange on account of the high 

 tides to permit of the existence of some species. Most of the collecting has been done 

 in shallow water and near shore, hence although 87 species have been obtained, the 

 probability is that many others exist in areas as yet untouched. 



Apart from the Passamaquoddy archipelago, one other point must be mentioned 

 and this at the other side of the Bay of Fundy. St. Mary bay, near Brier island, 

 Nova Scotia, must be a very satisfactory locality for hydroids. All the material sent 

 from there, apparently was obtained during one trip, July 29-30, 1913, and yet from 

 this material alone 30 species of hydroids were obtained. When that many were picked 

 up in indiscriminate collecting, the locality must offer fine opportunities for one looking 

 especially for hydroids. 



The Gulf of St. Lawrence has been touched at only a few points, Malpeque, 

 Gaspe, Seven islands, Anticosti, Bay of Islands, Newfoundland, and some individual 

 dredging trips. It is quite possible that in the gulf there is no single restricted area 

 that offers such a variety of conditions as that at the entrance to Passamaquoddy 

 bay, yet along the whole coast there is variety in plenty and in the vast area of the gulf 

 itself there are great differences in depth and in the nature of the bottom. While the 

 65 species already obtained may be representative, they must only serve as a sample of 

 what is to be found there. 



What is true of the Gulf of St. Lawrence is equally true of the Nova Scotia coast. 

 The near shore waters have been touched only in the vicinity of Canso at the extreme 

 east and at Barrington passage at the extreme south. The coast waters intervening 

 are studded with small islands among which are innumerable channels with suitable 

 conditions for a good food supply, in which no collecting has ever been done. The 

 small amount of deep water dredging done by the United States Fish Commission 

 gives some idea of the richness of the fauna in deep water. Of the 65 species from 

 this area, five were found on sargassum from the gulf stream. These were Syncoryne 

 mirahilis, Clytia noliformh Jhclia hyaliva, Sertularia cornicina and Plumularia 

 setaceoides, but the first two have also been reported from inshore. 



In making a comparison of the hydroids found in these three areas, it will be 

 noticed that of the 27 gymnoblastic species 25 have been found in the Bay of Fundy, 

 11 in the Gulf of St. Lawrence, and 15 off the Nova Scotia coast. The gymnoblastic 

 forms are always an uncertain quantity, particularly in general collecting. So many 

 of them are so delicate that they are soon past recognition unless they are preserved 

 when taken from the water. It is quite possible, therefore, that the Bay of Fundy 

 predominance is due to better preservation of material. Of the 26 species of Cam- 

 panularians, 21 were found in the Bay of Fundy, 17 from the Gulf of St. Lawrence 

 and 17 from the Nova Scotia coast, almost exactly the same proportion as the whole 

 number of species. Of the 7 species of the Campanulinidae, 3 were found m the Bay 



