CALCODES. 185 



(J. Head and mandibles longer than those of the female and 

 often very strongly developed. 



The legs are longer in the male than in the female, the front 

 tibia broad in the latter and more or less slender in the male. 



The ])rosternum may (lifter in the two sexes and sometimes 

 forms a sharj) doxniwardly direeted i)rocess in tlie male. In 

 some s)X'cies (C. rastanoptt^rus, parnji, etc.) the mentum is bare 

 in the female and eovered with a dense hairy mat in the male. 



The females of this genus are closely similar, but the males 

 vary greatly. In large male sjiecimens the head is often much 

 larger than that of the female, the front margin strongly 

 ridged, the anterior part of the head hollowed and the man- 

 dibles long and branched. In small specimens of all the species 

 the mandibles arc only a little longer than those of the female 

 and simi)ly serrate at the iimer edge, and some species (e.g. C. 

 pdrnji Leuthner, castanopterus Hoj^e) do not advance far beyond 

 this condition in their largest kno\m development. Of some, 

 however, few examples are yet kno\ni and it should always 

 be borne in mind that more highly developed phases may 

 occur than those which have been described. In some species 

 the most highly developed form constitutes a distinct phase 

 not connected bj^ intermediates with the lower stages, and this 

 phase may be rare. 



The genus C<dcodes is one of the most characteristic amongst 

 the insect genera of tropical Eastern countries. The large size 

 and bright colours of some of its species and the remarkable 

 development attained by the mandibles of many of the males 

 have naturally attracted special attention to them. All the 

 forms are easily recognizable by the com])letely divided eyes, 

 the absence of spines on the middle and hind tibice and the 

 structure of the ligula and maxillae. Thomson proposed a 

 separate genus for certain of the species in which the males 

 have no process behind the eye and the mandibles do not 

 attain a very great development and this has been accepted 

 by later authors. The tAvo features, however, are not always 

 associated ; the post ocular process occurs in all stages of 

 development in some species and highly developed mandibles 

 only occur in large individuals in any species. Generic charac- 

 ters confined to one sex are in any case highly inconvenient and 

 it is only necessary to place side by side females of such species 

 as C. cuvpra and parryi (representing the two t\'pes) to be 

 convinced of the impossibility of a generic separation. 



K(y to the Species of Calcodes (males). 



1 (36) Surface not metallic. 



2 (23) Upper .<?urf ace not entirely dark. 



3 (20) Elytra parti -coloured, yellow (or red) 



and black. 



