140 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



Notonecta undnlata. (Journal N. Y. Ent. Soc., vol. xm, 

 No. 3, 1905, p. 154.) 



Family Corixidse: "Egg of Corixa mercenaria" by L. O. 

 Howard, Insect Book', 1901, p. 273. Egg ovate; chorion 

 minutely chagreened, yellowish-white, shining; at the upper 

 egg-pole, centrally, a short, but rather robust, conical-shaped 

 chorial process. (PI. XII, fig. 7.) 



Some European entomologists are now adopting the charac- 

 teristic egg-types as a medium for the phylogenetic and sys- 

 tematic arrangement of the families. Our authors, describing 

 the life histories of North American hemipterous species, in- 

 vestigated the eggs mostly in relation to biological and 

 economic entomology, overlooking the important role these 

 remarkable egg-forms may play in the systematic study of 

 the order. But neither part should be neglected. For this 

 reason the writer thought it worth while to take an interest in 

 the study of North American hemipterous eggs, and describe 

 forms hitherto not known. This work is simply a summary, 

 a step in the direction of finding some new and valuable char- 

 acters for our classification. There opens a wide field for 

 further investigations; and the writer hopes that young stu- 

 dents may become interested in this subject, and fill up the gaps 

 in our scant knowledge of these beautiful forms of hemip- 

 terous eggs. 



Up to the present time no eggs have been observed of the 

 following families: 



Acanthiadse Saldidse. Nabidse. 



Ochteridse ~- Pelogonidse. Dipsocoridae = Ceratocombidae. 



Nerthridae^ Galgulidse. Isometopidse. 



Gerridae. Piesmidae. 



Mesoveliadae. Neididae = = Berylidae. 



Naeageidae == Hebridse. Scutelleridae. 



Henicocephalidae. Cydnidae. 



Emesidas. Thyreocoridae == Corimelsenidse. 



The original descriptions in this paper and accompanying 

 drawings are taken from eggs belonging to the U. S. National 

 Museum collection, from material of my own, and from an 

 additional, small, but valuable collection sent by Dr. W. D. 

 Hunter, to whom I feel much indebted. 



