250 [October, 



only is raised, the sound is thinner by half; and when the coxae are held down the 

 sound is not impaired. Geotrupes stercorarius, L., stridulates in a similar manner, 

 but much more feebly than G. sylvatievs. 



Aromia moschata, Grammoptera ntjicornis, Strangalia armata, and probably 

 most of our indigenous Cerambycidie, stridulate by a vertical motion of the hind 

 margin of the thorax upon the base of the elytra. Mesosa nubila also stridulates, 

 though so weakly that I could only catch the sound on placing the insect close to 

 my ear — out of my range of vision. 



Pelobius tardus raises such a " shout," as noted by Fowler, that one is at first 

 inclined to drop so uncanny an insect ; and I have been enabled to confirm Bedel's 

 observation on this head respecting Hydrobius oblongus, though I consider the 

 sound comparatively strong, especially when the beetle is just taken from the water. 

 Hydrous caraboides also stridulates distinctly, but in the last three species I have 

 not noticed the source of the sound. 



Erirrhinus vorax and E. validirostris both stridulate loudly by rubbing the 

 apex of the abdomen vertically upon the elytra ; the latter moving the while no 

 other part of the body, though in the former the sound is often accompanied by 

 wavings of the rostrum, which appears to be a warning attitude, and, with so well- 

 developed an organ, is doubtless a fearsome sight. 



Perhaps the most interesting instances of all are to be found in the $ $ of the 

 Mut ill idee. That of Mutilla europcea, as noted by Kirby and Spence, emits a 

 " sibilant chirping " ; this is caused by the friction of the abdominal segments upon 

 one another, and takes the form of two very distinct notes, of which one is produced 

 by the apical, and a deeper by the basal segments. That of Myrmosa melanocephala 

 always stridulates in like manner, though in only one note, feebly, seven times in 

 quick succession, and then pauses as though to take "breath." 



The above are the only cases I can instance at the moment as having come 

 under my personal observation, though many more are awaiting investigation. In 

 the Carabidce, Staphylinidce, Chrysomelidce and Hemiptera, however, protective 

 odours appear to take the place of stridulation ; and attention has recently been 

 drawn to a possible stridulating organ in Anopheles maculipennis by Shipley and 

 Wilson (Trans. Roy. Soc. Edin., 1902, p. 367).— In. : June, 1902. 



Alerteur.s. 



Proceedings of the South London Entomological and Natural His- 

 tory Society, for 1901. 8vo, pp. 76, with two plates. London : published at 

 the Society's Rooms, 1902. 



This annual summary of the work done by this old and useful London 

 Society is thinner than its immediate predecessors, chiefly on account of only two 

 papers being printed in full. But the reports of the excursions and ordinary 

 meetings are extensive, and in some cases evidently embody the pith of more 

 lengthy papers. Much of interest is to be found in these Reports, and also in 

 the Report of the Council and the Treasurer's balance sheet. The Society is 

 flourishing, and now numbers 174 members, and the balance sheet shows careful 

 financial supervision ; that there is a small but progressive demand for its publi- 

 cations on the continent shows that it is recognised abroad as of importance. This 



