[bailey] the diatoms OF NEW BRUNSWICK 59 



didyma occurs alike in St. John Harbor and at the mouth of the Nerepis, 

 ten or twelve miles inland from the latter. 



The conditions, other than those of salinity, which affect the 

 distribution of Diatoms are, in New Brunswick as elsewhere, depth 

 and purity of the waters containing them, the temperature of the latter, 

 the abundance or scarcity of ordinary Algae, and the existence or other- 

 wise of powerful tidal currents. In all these respects a contrast may be 

 noticed between the two coasts, southern and northern, along which 

 most of the collections have been made. 



The Southern or Bay of Fundy coast of New Brunswick is almost 

 everywhere bordered by high bluffs of very hard crystalline rocks, 

 the ledges at the base of which are thickly mantled with Fucus and other 

 littoral forms of marine algse. The water is usually deep quite to the 

 base of the bluffs and beaches are of rare occurrence. Tidal pools, 

 however, are not uncommon, and these serve to protect their contents 

 during the interval between the ebb and flow. Passamaquoddy Bay, 

 near which the Biological Station has been established, and where many 

 collections were made, is separated from the main body of the Bay of 

 Fundy by a chain of islands, but excepting these and the larger islands 

 of Campo Bello and Grand Manan, few islands are to be met with. 

 The tide about the mouth of the bay and in Passamaqvioddy is subject 

 to a rise and fall of about twenty feet and here the tidal currents are of 

 great force and rapidity, but at St. John the change is about thirty feet, 

 while at the head of the Bay, the change varies from forty to sixty feet. 

 The waters throughout most of the Bay are quite clear and free of 

 sediment, but towards the head become very turbid with suspended 

 mud derived from the softer rocks which there border it. Everywhere 

 the waters are very cold though somewhat warmer in Passamaquoddy 

 Bay than in the Bay of Fundy outside. The rivers which débouche 

 into the main bay have something of the character of fiords, but with 

 the exception of the St. John they have no great volume. The St. 

 John is unique from the fact that there is a barrier at its mouth, which 

 by damming the tide, causes an inward fall and flow, of which the 

 effect is felt for some eighty or ninety miles above its outlet. The 

 conditions for the study of estuarine forms are here, therefore, unsur- 

 passed. 



On the other hand the so called "North Shore" of the Province 

 is almost everywhere low. The adjacent waters are shallow, often 

 for considerable distances from the actual shore-line; islands and sand 

 bars, shutting in lagoons, are of common occurrence; large tracts are 

 occupied by growths of eel grass (Zostera) ; the rise and fall of the 

 tide does not exceed five or six feet, and through the summer months 

 the temperature is quite high. Tidal currents are feeble, while the 



Sec. IV, 1913—4 



