438 D. J. SCOURFIELD ON A NEW COPEPOD FOUND IN 



or even a month or two, specimens have begun to appear. From 

 the fact that the females have not been observed carrying ovisacs * 

 it seems possible that the eggs are dropped into the sediment to 

 lie dormant for a time, or even to be dried up and so perhaps 

 blown about by the wind. This might account for their distribu- 

 tion from one tree to another, although it is very probable that 

 insects, of which a number of forms occur in the same situations, 

 may also be a means of dispersal. In this connection and also in 

 relation to their peculiar habitat the wonderful vitality of the 

 animals may play an important role. They seem capable of 

 living for a very long time in quite small quantities of water 

 and with scarcely any food. On one occasion specimens continued 

 in evidence for four and a half years in a 3-in. x 1-in. glass tube 

 in which the collection had been brought home. The tube con- 

 tained nothing in the way of food, except the very innutritious- 

 looking original sediment, and nothing was added during the 

 whole time but a little clean water. Individual specimens, too, 

 have been kept for months in very small tubes with only the 

 merest trace of sediment and have remained perfectly active. 

 Such powers of endurance must evidently be of the greatest 

 value to them in their natural surroundings. 



Literature Referred to. 



1. Daday, E. von. Edesvizi mikroskopi allatok mongoliabol. 



Math. Termt. Ert., Vol. 24, 1906, pp. 34-77. 



2. Daday, E. von. Beitrage zur Kenntnis der Mikrofauna des 



Kossogol-Beckens in der Nordwestlichen Mongolei. Math. 

 Nat. Berichte aus Ungarn, Vol. 26, 1913, pp. 274-360. 



3. Douwe, C. van. Zur Kenntniss der Sussuasser-Harpacticiden 



Deutschlands. Zool. Jahrbucher. A bt. fiir Systematize, etc., 

 Vol. 18, 1903, pp. 383-400. 



4. Mrazek, A. Beitrag zur Kenntniss der Harpacticiden fauna 



des Siisswassers. Zool. Jahrbucher. Abt. f. Systematic, 

 etc., Vol. 7, 1893. 



5. Muller, F. Descripgao do Elpidium bromeliarum crustaceo 



da familia dos Cythei icleos. Arch. Museu National do 

 Rio de Janeiro, Vol. 4, 1879, pp. 27-34. 



6. Muller, F. Phryganiden-Studien. 3. Wasscrthiere in den 



Wipfeln des Waldes. Kosmos, Vol. 4, 1879, pp. 390 392. 



* See note on p. 440. 



