222 LEPIDOPTERA. 



sists of a system of spines, of which there are a dorsal and a 

 ventral series. I presume, strictly, all are dorsal, as being- 

 dorsal to the cloacal aperture, but in relation to each other 

 these groups may be most simply so described. The dorsal 

 set consists of two spines, one on either side, but not far 

 from the middle line ; only in accris do these tend to be 

 multiplied, apparently by being split up, rather than by 

 others being developed. The ventral set is more variable, 

 and consists of three or more spines on either side. These 

 pup« are not contained in a silken cocoon, but in cavities 

 formed by the larvas in rotten wood, bark, &c. Some, as psi 

 and tridcns, use rather more silk and will spin up in (Mhris, 

 or even go down into earth if no other resource is available, 

 whilst aceris, though loving some dead loose bark or such 

 material, spins an elaborate cocoon almost anywhere." " The 

 newly hatched larvae always have the eleventh segment pale." 

 " In nearly all the species the anterior' trapezoidal tubercles 

 have only one bristle, but two occur in one or two species." 

 " The full-grown larva is in each species a law to itself, but 

 where the larva is hairy, as in IcjJorina and accris, the hairs 

 ai'ise chiefly from the general surface, and the tubercles, as 

 bases for bundles of hairs, are not easily distinguished, whilst 

 in the non-hairy species, such as al'iii, each tubercle has one 

 bristle." " In this section the eggs are always laid separately, 

 and, so far as I know, in the wild state, are always laid 

 solitarily. They are not quite so flat as those of 

 Viminia." 



In the third group — Bisukia — " (his, twice ; sulcus, a furrow) 

 from the double depression that crosses the back of each 

 segment of the pupa." " The pupa is thick and squat, and has 

 two transverse depressions on the dorsum of each segment ; 

 the anal armature consists of short points. The cocoon is of 

 a hard, tough, but somewhat brittle silk, nearly black in 

 colour, and with always some indication of an opening at one 

 end, and sometimes an almost distinct line of division form- 

 ing a valve for the emergence of the moth." " The young larva 



