THE BRITISH NATURALIST. 



[October 



I have purposely avoided bringing in species with apterous or 

 semi-apterous females, as they will come into another division, and 

 their bodies are of about the same size as the males. 



In the Coleoptera the males are the larger in Lucanus, Dorcus, 

 Sinodendron, Dytiscus, and Acilius ; the females are the larger in 

 Prionus, Aromia, Lyrnexylon, Meloe, and Adimonia. 



In the Hymenoptera there is a vast difference in size in the sexes of 

 - me of the ants ; the males of Formica nigra, aliena, flava, and 

 umbrata not being half as large as the females ; the neuters of the 

 ants are wingless and of smaller size than either the male or 

 female. 



The males of bees and wasps are as a rule smaller than the females ; 

 however, those of this mellifica and Anthidium manicatum are larger. 



In the Diptera the males are the larger in Tipula plumbea, T. nigra, 

 T. lunata, Pachyrrhina annulicarnis, Pedicia rivosa, Limnophila bicolor, 

 and Idioptera pulchella ; the females are the larger in Tipula gigantea, 

 T. lutescens, and Symplecta punctipennis. 



In Trichoptera the male of Phryganea grandis is much larger than 

 the female. In Homoptera the female of the American Blight, Schizo- 

 neura lanigera, is more than twice the size of the male. 



III. — Disparity of Form. 



The males of Lobophora hexapterata and L. sexalata have a wing- 

 like lobe at the base of the hind wings, giving them the appearance of 

 being six-winged. The male of Eucosmia undulata has an appendage 

 at the base of the hind wings, somewhat resembling a brush. The 

 male of Colias edusa has a kind of glandular sac placed upon the 

 anterior edge of the hind wings near the base. 



The males of Dytiscus and Acillius, genera of the Coleoptera, 

 have smooth, the females rough, elytra. Amongst the Orthoptera, 

 the males may be distinguished from the females, in Decticus, 

 Phasgoneura, Platycleis, and Xiphidium by a transparent eyelet at 

 the base of the fore wings. 



In Hymenoptera the male of Ceiocsphala has the head curiously 

 tricornuted, and the females of Cratonius have the heads of a very large 

 size, but in Lyda both sexes have large heads. 



Females with very short ov no wings. — Most of the moths which 

 emerge in late autumn, winter, or early spring have wingless or 

 very short-winged females. These are Hybernia progemmaria, 

 H. aurantiaria, H. leucophaearia, H. rupicapraria, H. defoliaria, 

 Anisopteryx aescularia, Nyssia zonaria, N. hispidaria, Phigalia pilo- 

 saria, Cheimatobia boreata, C. brumata, Diurnaea fagella, Exapate 

 gelatella, Lemnatophila phryganella, and Dasystoma salicella. The 

 females of Orgyia antiqua and O. gonostigma, and the genera 



