June, 1917-] Hungerford: Life History of a Boatman. 113 



ceeded in rearing Ramphocorixa acuminata Uhler. He did so, how- 

 ever, by placing them in a very large aquarium used for breeding 

 mussels. " This was a zinc lined tank about two feet deep, and with 

 a superficial area of thirty or thirty-five square feet, with a layer of 

 soft mud in the bottom of an overflow arrangement by means of 

 which a quiet but constant stream of fresh water was kept circulating 

 through the tank." 



His attempts in confinement failed and he was inclined to attribute 

 these failures to the absence of proper food which he supposed to be 

 Ostracods, or similar organisms. 



Thus it has happened that until recently the factors necessary for 

 the continuous maintenance of certain forms throughout their de- 

 velopmental lives have remained unknown. However, when the con- 

 ditions have been discovered, the problem becomes somewhat less 

 difficult. 



In a paper on " The Food Habits of Corixids "^ the writer has 

 pointed out the reason for the failure to rear them in ordinary 

 aquaria. The source of the food supply of the boatmen lies in the 

 brownish sedimentary material at the bottom of the pool, and when 

 this is furnished in fresh supplies each day, they may be reared in 

 remarkably close quarters. The species here described were reared 

 in shallow glass petrie dishes, eleven centimeters in diameter, as 

 many as twelve individuals in each petrie dish. It will thus be noted 

 that they do not destroy one another after the manner of their fierce 

 predatory neighbors. 



Our experience with these has shown that they must receive care- 

 ful attention; the neglect of a day or two will result in disaster, and 

 it has been our custom to visit the pool for fresh corixid food daily.* 



The adults are said to pass the winter in the mud at the botton 

 of the pools and this year were aroused to activity during the warm 

 days of February.^ The eggs were laid, in the laboratory, on bits of 



3journ. N. Y. Ent. Soc, XXV. 



•1 Two broods were reared in ordinary glass aquarium jars, 14 inches in 

 diameter, in which there had been cultures of Nitella, without receiving any 

 attention other than adding water occasionally. 



5 The adults are more or less active in open water any time during the 

 winter. They were taken in numbers at Ithaca, N. Y., January 10, in a 

 spring-fed pool. 



