life-history of Porphyraspis tristis. 437 



fleshy protuberance on each side ; these protuberances are nar- 

 rowed towards the apex, and are fiu-nished with a few short bristly- 

 hairs; the 6th and 7th segments with the protuberances much 

 larger and rounded externally; the anal segment is provided 

 on its upper surface with a forked appendage, which is bent 

 forwards in the direction of the head ; the sides of this appendage 

 are chitinous, and are held together by narrow membranous cross- 

 pieces ; by its combined strength and lightness it seems admirably 

 adapted for carrying the heavy covering of excrement. Stigmata 

 eight on each side, arranged as in the European Cassididce. Legs 

 short and robust, provided with a few rather long bristly hairs ; 

 claws simple, strongly curved. Length of adult, 4^^ mm. 



Compared with the larva of Porphyraspis pahnarum, 

 as figured by Candeze, this species is much broader 

 behind. It also differs in having the head larger and 

 the protuberances on the 6th and 7th abdominal seg- 

 ments rounded externally instead of tapering to a 

 point. 



TRANS. ENT. SOC. LOND. 1884. PART III. (oCT.) 2 O 



