4 ENTOMOLOGICAL NEWS [Jan., '15 



The Aeshnines and Agrionines climb about on the weeds in 

 the pond or occasionally at the edges of the stream. Of the 

 Aeshnines Basiaeschna Janata, Aeshna constrict a and Anax 

 Junius are fairly common. Among the Agrionines, Argia 

 violacea is common, while Chromagrion conditum and Amphi- 

 agrion saucium are more rare. Lestcs rectangularis is quite 

 rare. Ischnura vcrticalis is exceedingly common and Neha- 

 lennia irene equal in numbers to the more abundant species of 

 Enallagma, which is represented by E. antennatum, B. diva- 

 gans, E. doubledayi, B. ebrium, E. exsulans, E hageni and 

 B. signatiim. 



There is evidently a seasonal change in the location of the 

 nymphs, at least of those of damsel flies. In the fall, Ani- 

 soptera and Zygoptera were abundant in the masses of weeds 

 in midstream, but there were none to be obtained there in the 

 springtime when they were numerous along the edges. During 

 the summer these forms oviposited mostly upon the weeds or 

 algal mats out in the stream. It is evident from this that the 

 eggs hatch and the nymphs remain in the stream until the 

 fall rains make the current too strong, whereupon they move 

 into the edges of the current and then downstream. 



II. Epiphytes and Epizoa. 

 The census of the population which settles upon the backs 

 of odonate nymphs forms an interesting record. Twenty-six 

 nymphs varying in size from 15 to 36 mm. were taken from 

 Cascadilla Pond between April 24 and June 20. They were 

 scraped with a tiny scalpel, the scrapings mounted in water 

 Ai a slide and studied under the microscope. Diatoms, green 

 ' and blue-green algae and a variety of protozoa and other micro- 

 scopic invertebrates were found. (See page 5.) 



Diatoms. — Besides the 19 species of diatoms recorded, there 

 were several species of Navicula and Synedra which were not 

 identified. These two groups were present almost constantly 

 and in abundance, while Gomphonema on its long stalks and 

 Encyonema in its gelatinous ribbon were frequently present 

 and often exceedingly abundant, Nitzschia sigmoidca was very 



