74 Annals Entomological Society of America [Vol. XIII, 



Kunckel (1890) pointed out that nymphs of the Acridelideidae 

 accumulated air in their crops, causing the "ampoule cervicale" 

 of each to become dilated which in turn raised the lids of their 

 earthen cases. He states further that the swallowing of air 

 bubbles is the chief means of molting. Peyerimhoff (1901) 

 states that the embryos of the Psocids regularly swallow air 

 bubbles to increase their size and enable them to exert the 

 necessary pressure at hatching. This writer also gives a brief 

 summary to date of the literature on the point. Heymons (1906) 

 has noted the increase in size of Pentatomid nymphs at hatching 

 by taking in air and adds that ForicuHdse do likewise at molting 

 and hatching. The phenomenon is perhaps more common than 

 a bibliography indicates. 



BIBLIOGRAPHY. 



Riley, C. V. 1876. On the curious egg mass of Corydalus cornutus (Linn.) In Proc. 



Amer. Ass. for Advancement of Science. V. 25, p. 275-279. 

 . 1877. The Hellgrammite. Corydalus cornutus (Linn.) In 9th Ann. Rept. 



of Noxious, Beneficial, and other Insects of Mo., p. 125-129. 

 Kunckel d'Herculais, J. 1890. Du r61e de I'air dans le m^canisme physiologique 



de Teclosion, des mues et de la metamorphose chez les insectes Orthopteres 



de la famille des Acridides. In Comptes Rendus de TAcad^mie des Sciences, 



V. no, p. 807-809. 

 Peyerimhoff, Paul de. 1901. Le meca'nisme de I'eclosion chez les Psoqucs. Jm Ann. 



Soc. Ent. de France, V. 70, p. 149-152. 

 Davis, K. C. 1903. Sialididae of North and South America. In Aquatic Insects 



in N. Y. State. N. Y. State Museum, Bui. 68, pt. 7, p. 442-487. 

 Heymons, Richard. 1906. tjber einer Apparat zum Oflfnen der Eischale bei den^ 



Pentatomiden. In Zeitschr. Wiss. Insektenbiologie. V. 2, p. 73-82. 



