176 Illinois State Laboratory of Natural History. 



H. ekthlipsis Gr. 



Taken by us but once, July 5, at an electric light in 

 Champaign. 



H. icciusali^ Walk, {genuinalis L>e6., Jbrmosalis Clem.). 



Although the moth of this species is the most common 

 hydiocampid about the University, it was not seen at 

 all at Havana. The probable differences between the 

 immature forms of this and the next species have al- 

 ready been mentioned. 



We have found the imago at electric light in Urbana 

 May 19, 31; June 3, 15, 26; July 5, 6, 7, 20, 21, 28; 

 Aug. 2, 17, 24; and at Lake Geneva, Wis., on Sept. 3. 



jy. ohllteralis Walk, {proprialis Fern.). 



The favorite home of this species is among the float- 

 ing leaves of Potamogeton nutans^ which often thickly 

 cover the surface of quiet water in large patches. The 

 amber-colored eggs [Fig. 8, 9] were first noted June 1, 

 and are laid in a long band just within the margin, on 

 the lower surface, of some broad floating leaf, usually 

 that of P. nutans. They are closely placed in a single 

 layer, in rows running parallel to the margin, the band 

 being about 3 mm. wide and including usually five or six 

 rows of eggs, the members of each row alternating with 

 those of the adjacent rows honeycomb-fashion. Their 

 long axes point to the margin of the leaf, and each q^^ 

 slightly overlaps those adjoining it on the inner side, 

 showing that the moth probably rests at the edge of 

 the leaf above and extends her ovipositor beneath it. 

 The band is usually an inch or two long. One leaf of 

 P. nutans in our collection, over three inches long, is en- 

 tirely margined with eggs, except a short interruption 

 at the side and another at the extreme base of the 

 leaf. These 9^'g bands were common in July, and a 

 few were seen in August. 



Larvae were obtained from them in the breeding-cage 

 July 13. The next day they had cut out minute oval 

 disks from the leaf, and webbed these to its lower sur- 



