150 Journal New York Entomological Society, tvoi. xxv. 



All the adult specimens obtained were ??, except the one and only 

 specimen of C. mocchus, which was a c?. The individuals were col- 

 lected partly while attacking the collector, partly from windows of 

 the greenhouse, Guyot Hall and the vivarium of Princeton Univer- 

 sity, partly in the act of egg-laying and on flowers and bushes. One 

 female C. callidus was taken in the evening of July 14 on a flower of 

 milkweed (Asclepias). 



The species were identified with the aid of the collections de- 

 posited in the New Brunswick Agricultural Experiment Station and 

 the Academy of Science in Philadelphia. The writer here takes the 

 occasion to thank Dr. Thomas Headlee, of New' Brunswick, and 

 Messrs. E. T. Cresson and Dr. Henry Skinner, of Philadelphia, for 

 their help. For material, I am indebted to Dr. Theobald Smith for 

 specimens of Chrysops from New Hampshire, and to Mr. Macy, 

 who was in charge of the Guyot Hall greenhouse, and who col- 

 lected considerable numbers of the flies. Others were collected by 

 boys. 



The Egg-laying Habits of Chrysops. 



Hart (1895) has described the egg-laying habits of Chrysops 

 mcerens Walker (syn. ccstnans Meigen). Hine (1903) describes the 

 egg-laying habits of C. callidus O. S. Part of these observations have 

 been duplicated by the writer, since at the time when the observations 

 were made the literature wasf not at hand, but as our knowledge in 

 general is still very incomplete, the following notes may add some 

 detail to the results previously recorded. 



Observations could be made on Chrysops callidus and one other 

 species of Chrysops, which could not be fully determined, since only 

 the eggs were found, and no specimen was caught in the act of lay- 

 ing. This species was probably C. nnivittatus. It is of interest that 

 the appearance of the egg-cluster in this species is very different 

 from that in C. callidus and the other species observed. 



Chrysops callidus is found ovipositing near ponds and streams on 

 semi-aquatic weeds, chiefly in the morning hours till after 11 o'clock, 

 from the latter part of May to the end of July. In oviposition, the 

 females alight on a leaf or reed, head pointing downward, and pro- 

 ceed to lay while moving slowly in a downward direction (Plate X, 

 fig. i). The eggs are laid in a cohesive mass or cluster, usually on 



