16 THE NAUTILUS. 



It flows for a distance througb meadow land in a valley ; here mol- 

 lusca are seldom found. The next portion continues through a val- 

 ley thickly wooded, with alders overhanging the water and covering 

 the narrow belt of marsh ; beyond these the steep banks and upper 

 land are covered with pinegrowth. Land shells occur rarely along 

 this area: Succinea ovalis, I'ntu/n xtriatella, Strobilops labyrinth ica, 

 Zonites exiguus etc., have been found here. The brook has a fine 

 lot of Margaritana margaritifera of large size and fine specimens. 

 Pisidium variabile, abditum and adamgii occur in the mud, the last 

 of these in an area of a few feet, but having some fine examples. 

 Plan orbit and Physa also occur sparingly. The third area is a mile 

 or two of tide marsh ; here one may study the problem of salt and 

 freshwater distribution. The writer gave an afternoon to this work 

 a few days ago with the following result: In the upper quarter of 

 the marsh Pisidium occurs more or less abundantly, and Amnlcola 

 is to be found in great profusion ; following the windings careful 

 siftings were made. Pisidium disappeared after the first quarter of 

 the distance to the sea ; I am quite sure that salt water has little or 

 no influence here. Amnicola was met with where Pisidium had 

 disappeared, but only for a short distance. The portion followin.i: 

 this in the second quarter was entirely wanting in shells, but grad- 

 ually salt water forms showed themselves, i. e., Macoma and Lituriiia. 

 The marsh itself now gives an interesting field of study. Plant life 

 is very rich, but that is not our subject. Pot holes now reveal the 

 presence of multitudes of Liturinella minuta living on the thread- 

 like marine plants. The Goose Fair Brook enters the sea in the 

 middle of a long beach, generally known as Old Orchard beach. 

 Its marine shells are chiefly Litorina littoria and Macoma, the latter 

 often badly eroded. I have seen living specimens with the animal 

 exposed in places where erosion had destroyed the shell. Not far 

 from the shore there must be beds containing Tellina tenera, Cero- 

 ii in nrctfita and others, as specimens are washed up by storms. I 

 trust that these few observations may help to settle the question of 

 the distribution of marine and freshwater forms. At any rate this 

 is one point in the evidence. 



SOME NEW OR RARE SPECIES OF MARINE MOLLUSCA RECENTLY 

 FOUND IN BRITISH COLUMBIA. 



The following note may be of interest to collectors of West Coast 

 Mollusca. It adds sixteen species to our fauna not hitherto" reported 



