Browne — Fauna and Flora of Valencia Harbour, Ireland. 687 



part of the year, from January to April, it is rather scarce, and 

 only a few apecimens are occasionally taken. Up to the 

 end of March most of the specimens are ahout 6 mm. in 

 length; but a few are larger, ranging up to 10 mm. In April 

 fine adult specimens are taken, 25-30 mm. in length. In May 

 large specimens are occasionally taken, and young ones, ahout 

 2-3 mm. in length, make their first appearance. During May 

 and June the adult specimens gradually disappear, and their 

 place is taken by their more numerous offspring. In July 

 Tomopteris becomes fairly common, and at times even abundant- 

 Most of the specimens are about 6 mm. in length, but some 

 are quite young stages, about 2-3 mm., and a few belong to 

 later stages, 10-13 mm. The association of early and inter- 

 mediate stages tends to show that the breeding time of the 

 adults extends over several months. The early stages taken 

 in May probably come from eggs liberated in April, and are 

 represented by the larger specimens taken in July; and the 

 early stages taken in July come from eggs liberated at the 

 beginning of June. During August most of the specimens are 

 5-12 mm. in length; but a few up to 30 mm. are taken. 

 Prom the middle of September until late in October is the 

 breeding season of this summer generation ; and early in October 

 young stages, 2-4 mm. in length, make their appearance, and 

 soon become abundant. At the end of October there is again 

 a mixture of different stages, just as in May, consisting of 

 young and intermediate forms 2-12 mm. in length, and a few 

 adidts over 20 mm. About the middle of J^ovember a rapid 

 decrease in numbers takes place, and by the end of the month 

 Tomopteris becomes quite scarce. What becomes of all the 

 numerous stages is a problem yet to be solved. Probably 

 the winter storms may account for the destruction of a good 

 many. 



It is clear from the sudden appearance of numerous young 

 specimens that there are two distinct generations in a year, 

 one in the spring and the other in the autumn. The interme- 

 diate and adult specimens taken in the spring are, I believe, the 

 survivors of the autumn generation. These have passed safely 

 through the winter with a considerable loss in numbers ; but 

 their offspring, reared under more favourable circumstances, 

 apparently do not suffer such a loss in numbers, and produce a 

 larger generation in the autumn. 



