36 Annals Entomological Society of America [Vol. X, 



the egg-capsule except at the carina and in the depressions between 

 them where it is distinctly thicker. The average thickness is about 

 0.0048 mm. The exochorion and endochorion are distinct, all variations 

 in thickness being confined to the former which is composed in part of 

 very minute, closely set, columnar units. For the greater part of its 

 length, the median carina has an acute crest (Fig. 3) but near the ends it 

 gradually merges into a lower ridge whose crest is broad and slightly 

 rounded. 



Under magnification, the surface of the chorion, except the region 

 including the longitudinal carina; and fossa, appears faintly but def- 

 initely reticulate, being composed of polygonal units (Fig. 4) which 

 vary somewhat in shape and size but are usually hexagonal and more 

 elongated in the direction of the long axis of the egg. Their average 

 surface dimensions are about 0.112 and 0.056 mm. They contain 

 numerous, minute, circular, uniformly distributed structures which 

 give 'to the surface a granular appearance. These structiu-es are of 

 unifonn size and appearance and are never contiguous. Structurally, 

 they seem to be the ends of the columnar units which compose a great 

 part of the chorion. Exclusive of the fossa and carina?, they are present 

 over the entire surface of the egg, being absent only on the narrow, 

 homogeneous zones which separate the hexagonal areas. 



Oviposition has not "been observed and the writer has failed to secure 

 eggs from females placed in the aquaria with food plants for that pur- 

 pose. The identification of the egg has been made from a comparison 

 with fully developed eggs dissected from females. The characteristic 

 size, shape, and external structures, such as the carinse, fossae, and hex- 

 agonal areas, and a microscopical comparison of transverse sections of 

 the eggs leave no doubt as to their identity. In addition, the writer 

 secured a large number of eggs in various stages of development on the 

 petioles of the water-lily and demonstrated the fact that the resulting 

 larvae develop the characteristic effect on the petiole, ultimately pro- 

 ducing adults of H. confluens. 



In connection with the dissection of females for developing eggs, it 

 was noticed that, as in many other insects, there is a definite relation 

 between the position of the egg in the ovariole and the shape of the 

 completely fonned egg. The larger, more pointed end is nearer the ovi- 

 duct while the smaller, blunter end, which is characterized by a small 

 terminal concavity, is nearer the terminal filament. It is then possible 

 to detennine accurately in the egg already deposited what was the 

 previous relation to the reproductive organ. 



Place and Method of Deposition. — The eggs are deposited 

 singly at irregular intervals on the surface of the floating leaf 

 petioles of the yellow water-lily {Nymphcea americana (Pro- 

 vancher) Miller & Standley). No eggs were found on the 

 petioles of the submerged leaves and none were observed on 

 other aquatic plants occurring in the vicinity of the yellow 



