Stridulating Organs in Golcoptcra. 441 



adapted for the production of sound, but judging from 

 the excellent figures which Schiodte has given of them 

 (" Naturhistorisk Tidsskrift," Ser. 3, Vol. IX, 1874), and 

 from what little I have seen of them in one or two species, 

 I should consider them very well adapted for the purpose ; 

 and such is, I believe, their true function. 



2. Strididating organs on the prothorax ami front legs. 



These are found only in a relatively small number of 

 genera and species, but some of them are very interesting 

 as being amongst the most perfect of their kind. The 

 stridulating apparatus met with in several species of the 

 Carabid genus Siagona has recently been figured and 

 described by MM. Bedel and Francois in the " Bulletin 

 de la Soc. Ent. de France " for 1807. It consists of a 

 transversely striated or ridged carina running along under 

 each side of the prothorax, and of a very small striated 

 area on the outer face of each of the front femora, this 

 area being so placed as to come in contact with the ridge 

 on the prothorax, when the femur is rubbed along the 

 side of the latter. An arrangement somewhat similar to 

 this occurs in the Bostrychid genus Fhona-pate, Lesne 

 (see PL VII, figs. 7 and 7a), and has been described by 

 M. Lesne as one of the distinctive characters of his genus. 

 In the females of Phonapatc each of the anterior femora 

 has a well-defined longitudinally striated area on its outer 

 face close to the apex, and when the femur is rubbed 

 along the side of the prothorax, this area is made to 

 scrape against a series of six or seven short oblique ridges 

 placed near the hind angle of the thorax. The whole 

 apparatus is one of the most perfectly developed met with 

 amongst the Coleoptera, but what makes it especially 

 remarkable is the fact that it occurs only in the females, 

 the males, so far as is known, being without stridulating 

 organs of any kind. This is the only instance known to 

 me, in which the stridulating organ of insects is confined 

 to the female sex. (The bed-bug may prove to be another 

 exception, the complicated apparatus discovered by Dr. 

 Ribaga in the female of this insect being conjectured by 

 him to be a stridulating apparatus.) 



In Onialoplia hrannca, the stridulating area is situated 

 on the prosternum. Westring has long since pointed out 

 that the dorsal or inner face of the intercoxal part of the 

 prosternum is transversely striated, and that stridulation 



