329 



places that are daily covered by the tides and in places that are not. Its 

 outer limit is 14 N., 4 E. (map 2). They are very abundant in the gravel 

 which covers the wooden platform and also in the region of the tidal drift, 

 especially under the newly washed up sea-lettuce (Ulva). In regions daily 

 covered by the tide it is rarely found except in gravel covered areas. By 

 crawling under the gravel it prevents itself .from being washed away 

 and protects itself from aquatic enemies. Its actions may be readily ob- 

 served by hunting for them as the tide rises and the digging a channel 

 around the place where they are found. As the water rises, they will 

 run from place to place, darting under one stone only to leave it for 

 another. They may approach the channel, but will rarely attempt to 

 cross it. Before the tide has completely submerged the place, the bernbida 

 will crawl under the gravel to remain there until the tide retreats. When 

 the place is covered by the tide, they may be found at a depth of from 

 three or four inches. The water, when it covers them, encloses a large 

 bubble of air under their wings. 



Their action may be easily determined under artificial conditions by 

 placing them in jars containing moist sand and gravel and slowly filling 

 them with water. Several times, when filling the jars, I poured the water 

 in so rapidly that some were swept to the surface. They would then swim 

 wildly on the surface; but when a grass stem was thrust into the sand so 

 as to extend above the surface of the water, they would swim to it and 

 crawl down into the sand. The bubble of air under their wings is so large 

 that should they lose their footing, they will immediately rise to the 

 surface. Their ability to withstand submergence is wonderful. At the 

 end of one day the bubble of air will have almost disappeared and they 

 will have become stupid. By the above gravel jar I kept eight out of ten 

 specimens alive for three days in sea water. Several recovered after five 

 days' submergence, showing a great resistivity to drowning. 



This beetle, as well as the Heterocerous undatus and Salda sp(?) 

 lives on the carrion of the small animals so abundant in the between tides 

 zone. 



Hetekocerus Undatus. 



This beetle is very rare in this area. Several were found between 

 4 and N., to 12 and 16 E. (Map 2.) They live in burrows in the ground, 

 only venturing out for food at low tide. Their resistance to drowning 

 is equal to that of the Bembidium. 



