THE MOUNT DESERT REGION L15 



I. angustior (Gyll.) (2595). S. W. Harbor ice* ponds, July 



14. 

 I. BiGUTTUi/rs (Genu.) (2598). Common in small ponds and 



pools from Aug. 1 to Sept. 

 I. confusus Aube (2600). Station F318. 

 I. sp. Station F384. 



Coptotomus Say 



C. interrogate (Fab.) (2610). New Mill Pond in Aug. 

 and at Stations F186, F383 and F389. 



Rantus Boisduval and Lacordaire 



R. zimmermanni Wallis. A northern form and this is the 



first record from Maine. Station F383. 

 R. binotatus (Harr.) (2616). Two individuals taken in New 



Mill Pond, July 21, '34 indicating' scarcity. 



Colymbetes Clairville 



C. sculptilis Harr. (2632). Pond near Bar Harbor, June 9, 

 '27, and Gt. Heath, July '41. 



Dytiscus Linnaeus 



D. verticals Say. (2638). This species had never been seen 

 on the Island until taken in large numbers at the same time 

 and place as that next below. 



D. dauiiicus Gebl. (2645). This species is found in very few 

 numbers in the smaller ponds. On July 30, '35, a man in 

 Tremont reported that his trout were being eaten up by 

 lizards. Upon investigation they proved to be the "water 

 tigers" of this and (D. verticalis) and the pool was fairly 

 swarming with the adults, they having evidently hatched 

 during the previous week. Upon investigation, this spring 

 which had been made into a pool, had no connection with 

 any other body of water, and was on a hill and therefore 

 the absence of the eels, which are the common enemy of this 

 family, permitted them to multiply in peace. 



D. sp. A "tiger" in the house Bar Harbor, June. (Dr. Thorn- 

 dike.) 



