277 
Fig. 1 represents the freshly hatched larva, Stage I, drawn with 
the tubercles, hairs and spines; @é/', the first, ad/°, the sixth, pair 
of abdominal legs. 
Fig. 2 represents the armature in StageI; @, part of an ordinary 
finely spinulated hair; 4, one of the smaller spinulated hairs situated 
on the head, and also on the tenth abdominal segment ; ¢, a group 
of three venomous setz, showing the glandular cells (fc.) at the 
base, by which the poison is secreted. 
Fig. 3 represents the cells (sc.) in the hypodermis which secrete 
the sete, and the poison-cells (fg/c) which secrete the venomous 
fluid filling the setee or spines, and which makes them so irri- 
tant and annoying when the spines break off from the tubercles 
bearing them. 4 is a group of setz arising from a subdorsal tuber- 
cle ; cuwz., the cuticle; y., the hypodermis ; sc., the enlarged and 
specialized cells of the hypodermis which secrete the spines them- 
selves ; fe/c, the nuclei which secrete the venomous fluid which 
fills the cavity of the seta (s.), seen at fin a broken spine. B, a 
short entire and a long broken seta; fg/c, four poison cells; p., 
the poison in the hollow of the spine. 
Fig. 4. Section of a subdorsal tubercle from a larva in Stage I. 
sc., the setigenous cells, one for each seta; Ag/c, nuclei by which 
the poison is secreted ; s., seta; #., poison in middle of a broken 
spine ; cu¢., cuticle; sd. ¢ub., spinulated surface of the subdorsal 
tubercle. Author de?. 
Larva, Stage /7.—Length, 3 mm. (Pl. V, Fig. 5). It differs from 
the previous stage chiefly in the head being nearly covered or over- 
grown by the hood-like prothoracic segment, so as to be almost as 
completely covered by it when extended as in the later stages. 
The short stiff setae are white instead of brownish at the end; the 
white hairs are, perhaps, more abundant, and the body is slightly 
thicker. The second and third thoracic and seventh to ninth pair 
of abdominal tubercles are now larger than the others. There are 
now about twelve crotchets on the middle abdominal legs. 
It molted July 16-17, hence the length of this stage is 67 days. 
Fig. 6 represents the seventh abdominal segment of this stage. 
@, the dorsal tubercle, with 12-13 poison-bearing sete, with 
brown tips, and five long very finely spinulated hairs, which are 
about twice as long as the segment is thick; sd., the subdorsal 
tubercle bearing about twelve venomous setz, and two or three long 
spinulated hairs ; sf., the spiracle, and directly behind and a little 
