1884. | Zoölogy. 195 
spring attack that does the whole mischief to the farmer who 
knows nothing concerning the autumn brood. 
I have, moreover, been led to believe that an enormous destruc- 
tion of the “ flax seed ” occurs during the winter, especially in the 
roots, which are entirely killed by the fly. I have often dug up 
and examined such roots during the winter and have many times 
found the pupæ nearly all dead and rotten. If further examination 
should confirm this observation we have an efficient cause check- 
ing to a great extent the excessive multiplication of this pest. 
ZOOLOGY. 
Notes on American Mepusa.—No group of marine animals 
presents a more fascinating field for the discovery of unknown 
facts than the Meduse. As in the progress of science isolated 
observations may come to have a value greatly beyond their appa- 
rent significance, I have thought it best to publish a series of dis- 
connected notes on these animals. Many of them have been in 
MS. for some time, and I have preserved them in this form with 
the belief that new opportunities might give me such additional 
observations as would enhance their value. Many notes, and 
Some of the most important, have already become antiquated 
through the studies of others. The remainder are presented be- 
Paying cut (Fig. 1). 
ae Most important 
differen as 
ce 
and the adult is the 
ii Ae size of the 
projection of the 
bell. This 
Fic. 1.——Dinematella cavosa. 
