168 COLEOPTERA. 



normal members of the Coleoptera. Either this is 

 the true history of their evolution, or we must adopt 

 the improbable supposition that the Rhynchophora 

 (weevils) have had a mode of evolution which is not 

 recorded and epitomized in the development of the 

 most highly modified existing forms of this order, and 

 the modifications exhibited by them have not been 

 affected by the past history of their own group. 



The extraordinary specialization shown in the males 

 of Stylopidae should be noticed in this connection. 

 They have slender, curiously crooked appendages, 

 which resemble the halteresof theDipteraand Coccidje, 

 but which occur by the reduction and deformation of 

 the fore- wings and not of the hind- wings. The small 

 prothorax and mesothorax, the huge metathorax and 

 comparatively small abdomen, form a strange contrast 

 with the usual outlines of beetles, and the arrested 

 development and degraded structure of the parasitic 

 female remind one also of the condition of the same 

 sex in the Coccidae. The extraordinary parasitic 

 genus, Sitaris, passes through four larval stages, includ- 

 ing a quiescent larval stage, called by M. Fabre a 

 pseudo-chrysalis, and this, as stated by Lubbock, re- 

 minds one of the pupa of Diptera. The forms of the 

 adults are, however, more normal than in Stylops, the 

 elytra and prothorax being also less reduced. 



The equally interesting researches of Riley upon 

 the development of blister-beetles, and the remark- 

 able series of hypermetamorphoses through which 

 Epicauta vittata passes have been described upon 

 pages 157-159 of this Guide and illustrated in Figs. 

 97-1 1 1, 113. This is an exceedingly valuable series 



