728 Mr. Gilbert J. Arrow on 



ridges much less fine and close than those of Gcotrupcs 

 stercorarius. In B. frontah (PL XXXVI, figs. 7, 7a) 

 the bands are more numerous, and very unequal and 

 irregular. They occupy the whole centre of the inner 

 fjxce of the coxa, and their component ridges, which are 

 fine and close near the upper edge, become gradually less 

 so as they recede. These short ridges do not anywhere 

 produce the appearance of " striae," nor are there any strise 

 in the coxal cavities, but within the posterior margin of 

 each cavity is a single slightly oblique chitinous fold, so 

 sharply elevated as to cause a slight depression behind it, 

 in which are a few long hairs. 



The genus Bolhoceras is a very large one represented in 

 all the great land areas of the world, but it is remarkable 

 that, so far as my observations have gone, there is no 

 trace of similar apparatus in species inhabiting any other 

 country than Australia, nor is it found in the majority of 

 Australian species. My inquiries have not produced any 

 further information as to the vocal powers of the genus, 

 nor is much known as to the habits of the species, which 

 are very retiring. I have found records by French 

 naturalists, however, of the possession of the faculty by 

 Bolboeeras (jallicum, which have led me to make a thorough 

 examination of that species. As a result I have arrived 

 at the conclusion that sound is here produced by means 

 differing entirely from any hitherto known to entomologists, 

 viz. by friction between certain parts of the wings and 

 abdomen, 



M. Fabre, in his "Souvenirs Entomologiques" (1900, 

 p. 182), describes the species mentioned as uttering a 

 sound wliich is very faint but much more sweet and 

 musical than that produced by any other beetle known to 

 him ; but he does not seem to have formed any opinion 

 as to the part of the body from which the sound pro- 

 ceeded. An earlier record, in Mulsant's " Coleopteres de 

 France" (LamelL, p. 352), states that Solier was led to 

 discover a specimen of the same sjDecies by the loud sound 

 it uttered, but this is not consistent with M. Fabre's more 

 precise account and, as a second-hand report, must be 

 received with reserve. The structures which I believe to 

 constitute the musical equipment of this and allied species 

 of its genus do not appear capable of producing much 

 volume of sound. 



An examination of the upper surface of the abdomen 



