1871.] 137 



and there is only a comparativoly imperfect series of tlio lines on the tliird abdominal 

 segment, with some still more imperfect litnes on the second and fourth segments, 

 and the stridiUating power of the species is comparatively slight. In some of the 

 metallic species (with the peculiar developed pygidium) the inner surface of the 

 femur is finely and densely rugose, but there is no stridulation produced by its 

 friction against the abdomen ; and in some of the red-legged species the inner surface 

 of the femur is nearly smooth. 



In the L. nigrita group there is no stridulating power. 



So far as I am aware, stridulating power arising from friction of the extremity 

 of the femur against the sides of the abdomen has not yet been indicated in tlio 

 order Coleoptera. 



Among the Lamellicorns there are many varieties of stridulating by peculiar 

 apparatus arranged for the purpose, so that one is inclined to believe that the power 

 of making a creaking noise is of some value to the species possessing it. Whether 

 it is of use by making some enemy who has seized an individual abandon it from 

 fright or surprise, ouly direct observation can show; but, judging from the loud 

 noise produced in L. Latreillei on the dead specimen, I can well suppose that dm'ing 

 life, when the noise is probably louder from the more perfect adaptation of the parts 

 to one another, the sound produced may be really of use in this way. — D. Sharp, 

 ThonihUl : August llth, 1874. 



Note on Aulacoihorax exilis, Boheman. — In the "Eiigenies Resa," Boheman 

 has described and figured (p. 35, pi. 1, fig. 1) a small Coleopterous insect from Taliiti 

 under this name. The insect is placed by him, without any indication of doubt, in 

 the family ScydmcBiiidcB ; but the figure of the species, and a magnified representation 

 of its leg, point it out as belonging to the Tetranierous series of Coleoptera, the tarsi 

 bewaring the characteristic structure of that group. I should suppose it to be probably 

 an Anthribid, alhed to Choragus or Xenorchestes ; but possibly it may bo a Brucliid, 

 aUied to Urodon. The generic description throws no light on the insect, for the 

 charaetei-a given can scarcely be considered generic,' most of them, indeed, being 

 reiterated word for word in the specific description. As the genus is ranged in tlio 

 ScydmmnidcE in von Ilarold's catalogue of Coleoptera, I suppose that Eoheman's 

 error has not yet been recognized, so I have thought it well to call attention to it. — 

 lu. : 29<A September, 1871. 



On the mode of stridulation of Coranus sulapierus, De Oeer. — In the Mittheil. 

 d. schweiz. ent. Gesells., iv, p. 159, Herr O. M. Renter lias a note on this subject, 

 the result of his recent observations. He says that the stridulation, which was first 

 noticed by De Geer, is not caused in the manner in which Westwood, after Gourean, 

 states that it is made in some species of Reduviidce, especially Peirates stridulus, 

 namely, by tlic friction of the neck within the prothoracic cavity ; but tliat although 

 Coranus, when it begins to stridulate, inclines its head up and down so that the neck 

 moves to and fro in the pronotum.yet it is not by this means tlio sound is produced. 

 The insect moves the extreme point of its rostrum up and down the longitudinal 

 channel of the presternum, and only then the sound comes forth ; when the rostrum 

 was removed the stridulation ceased. Viewed under the microscope, the channel of 

 the prosternum was seen to be vei-y finely and closely striated transversely, and had 



