Zoology.-] NATURAL HISTORY OF VICTORIA. [Insects. 



group of three similar ones on each side of the base of the abdomen ; anterior point 

 of the head produced into a slender stem in front of base of antennae, about 1 line 

 long", terminating in a bifid fork arched downwards ; the pupse are fixed in groups 

 of about 40 or 50, closely packed communities attached to a sheet of white silk web 

 often 1 foot or more in length and 6 or 8 inches wide, binding together several of 

 the terminal twigs of the Casuarina or she-oak tree which they frequent, each 

 individual being- fastened by the tail and a thread across the anterior part of the 

 abdomen at various inclinations from the horizontal to vertical with the head up. 



Reference. — Papilio Harpalyce (Don.), Epit. Ins. N. Hoi., 1. 18; Pieris, id. 

 (Boisd.), Sp. Gen. Lep., p. 458. 



The family Pieridce, including the majority of " white " butter- 

 flies, like the family Papilionidce, has the six legs perfectly 

 developed, but the former differs from the latter in wanting the 

 spines on the anterior tibiae. The sub-genus Thyca, to which the 

 present beautiful species of the old genus Pieris belongs, is readily 

 distinguished from the other divisions of the genus by having only 

 one subcostal nerve, marked a in the woodcut, given off before the 

 end of the discoid cell. It is a remarkable 

 circumstance that Doubleday and West- 

 wood state that none of the pupae of the 

 family Pieridce are ever bifid in front, while 

 the present species and the T. Aganippe 

 figured on our next plate have the anterior 

 process most distinctly forked and arched H aS&?fiffi!SJ±J*iS 



, 1 rr ,_ -i-ip characteristic single subcostal nerve. 



downwards. Ihere are two broods of 



this species in the year, one appearing towards the end of August 

 and the other towards the end of February, remaining about sixteen 

 days in the pupa state ; the larvae are found on the weeping 

 species of Casuarina and feed on the parasitic Loranthus found 

 growing upon it. 



The present species is remarkable for the extraordinary habit of 

 spinning a large white silken sheet like a tough cobweb on which 

 to attach the pupae in large groups of very numerous individuals 

 closely placed side by side. 



As Mr. Wallace has noted that certain islands north of Australia 

 have the individuals of the species of white butterflies distinguished 

 from the individuals of the same species found in other islands by 

 the greater or less angularity or acute pointing of the tip of the 

 upper wing, it is interesting to note that in this species, although 



" [ 34 ] . 



