‘THe Brotocy or EpHypRA SUBOPACA LOEW 601 
November 2. Considerable frost; flies Teny scarce in the pools, but 
numerous in the overflowed areas. 
November 5. Very heavy frost and thin ice; dies on ice hardly able to 
move when turned over. 
November 7. Heavy frost, and warm, bright sunshine; flies lively, 
staying on ice; six newly emerged flies and three mature flies died. 
November 22. Frost and snow; two mature adults found; one newly 
emerged fly died. 
November 28. Snow; no flies found. 
M ating 
Mating was observed on June 30. The male frequently jumped upon 
the female, trying to mate, but such attempts often resulted in failure, 
the female being unresponsive. He clasped the front of the female’s 
head from behind with his front legs, while the middle legs held onto her 
mesothorax and his hind legs onto the posterior third of her abdomen. By 
holding her fast with the two anterior pairs of legs, his hind legs were then 
able to move freely, rubbing on the female’s genitalia continuously for about 
thirty seconds. The female then turned the tip of her abdomen upward. 
The male’s abdomen was held in its usual position while a slender and 
pointed penis was protruded downward and inserted into the genital 
opening of the female. Copulation thus took place and lasted about four 
or five minutes. Then the penis of the male was drawn out, exposed for 
a while, and was finally withdrawn into his abdomen. He remained on the 
female for a few minutes before jumping away, but at times the male 
has been noted to hold the female under his feet for more than an hour. 
THE EGG 
» 
Oviposition 
Oviposition seems to be a very brief procedure. The writer observed 
a single female oviposit seven times within twenty minutes. Each time 
a single egg was laid on the water surface by the female’s merely touching 
the latter with her ovipositor. The eggs thus laid immediately sank to 
the bottom. 
Description 
The egg is elongated oval in shape and meastires 0.9 millimeter in 
length. Both ends are practically equal in breadth and the egg is slightly 
