38 TBANSACTIONS LIVEBPOOL BIOLOGICAL SOCIETY. 



red mites (Bdella longicornis) . This was notably the case 

 on April 18th, and again on May 18th, but was noticed to 

 a less degree on several other occasions. Once during the 

 winter on entering the laboratory after it had been shut 

 up for a few days we found the floor, tables, shelves, win- 

 dow ledges, and even dishes on the highest shelves, covered 

 with great numbers of the dead Amphipods. On April 18th 

 an unusually high tide occurred, and the curator and others 



Fig. 3. The Laboratory at Biological Station, Port Erin, 



noticed that the steps leading up from the beach were 

 swarming with Amphipoda. On watching them it was 

 found that the Amphipods were coming up in great num- 

 bers from high-water mark, that they jumped up the 

 steps (see fig. 3). and even climbed the vertical concrete 

 wall surrounding the station to a height of several feet. 



