180 ENTOMOLOGICAL TOUR. 



females, who in the proportion of about one to fifty of their 

 partners, were sitting sluggishly on the stems of the grass. I 

 continued my walk for about three hundred yards, without 

 perceiving any diminution of numbers. I then measured off a 

 square foot, and counted within that space thirty-seven ; and 

 they did not appear thicker in that spot than in others. Though 

 the species is still abundant in the season, I have never since 

 witnessed an assemblage like this. About noon, they may be 

 seen in sunny gravel-pits, the males soaring about in hawk- 

 like circles ; and when they alight, resting with the wings 

 expanded, and ready to take flight on the least shadow ap- 

 proaching. I know of no species in which the disparity of 

 numbers is so great as in the present. In this respect, B. 

 Johamiis perhaps come next. In B. Marci and B. clovipes, 

 the difference is still less, and I believe scarcely exists in 

 B. hortidanus. This difference of numbers in the sexes is a 

 remarkable point, and must be connected with something in 

 the economy of the species which exhibit it. To mention 

 another instance, I have seen hundreds of Pezomachits fas- 

 ciatus 5 , yet never met with a male, nor has any collector of 

 my acquaintance one of that sex. This circumstance might 

 seem to give support to Geoffroy's opinion, that the males of 

 the Pezomachi are winged, in which case it would be more 

 easily overlooked, were there any of our common - winged 

 male Crypti at all resembling it, and did we not know the 

 males of several closely allied species to be like their partners. 

 For other instances of the males being quite unknown, I may 

 mention Megaspilus riibi (Microps Ruhi mlhi), Ceraphron 

 melanocephalus, Cryptus sticticus, F. Sec. ^ 



Art. XVIII. — Entomological Tour in So?ith Devon. By 

 Messrs. Chant and Bentley. 



Sir, — If you consider the following remarks worthy a place 

 in your Magazine, they are quite at your service. We thought 

 they might in some degree amuse the general reader, and also 



•* We regret to see no reference in this valuable paper to Macquart's " Inscctes 

 Dipleres du Nord de la France," a work in which so many new species of Diptera 

 have been described, that we fear tliei-c is a probability of some confusion as t» 

 names. — Ed. 



