POLYCHAT LARVA, 611 
and third segments (Pl. II., fig. 24) each bear a long 
(130) notopodium immediately behind a bunch of short 
(500) setae; and a neuropodium of the same dimensions 
as the notopodium. Immediately im front of the neuro- 
podium is a tuft of setae consisting of a single straight 
seta, and first one, then two, and in the oldest specimen 
of all (in the anterior of these segments at least) three 
shorter stout curved setae. Between the dorsal and 
ventral rami there is a small round protuberance bearing 
hair-like processes as on the first segment. The fourth, 
fifth and sixth segments (PI. II., fig. 25) resemble the 
second and third, except as regards the ventral bunch of 
setae, which consists of two straight stout spines and three 
or four much smaller ones; the small rounded pro- 
tuberance, moreover, is not invariably present on all these 
seoments. The next five segments (PI. II., fig. 26) 
resemble the last three, except that both neuropodium and 
notopodium reach a length of about 2004, being produced 
distally, as mentioned above, into a slender cylindrical 
“handle”; one of the dorsal setae, too, is markedly 
stouter than the rest, resembling the two strong setae of 
the ventral bunch. The remaining segments also show 
this stout dorsal seta, but otherwise resemble segments 
3-5; after the first four or five of them, however, the 
occurrence of these special setae becomes irregular, and 
still nearer the posterior end they are not to be found 
at all. 
Two fixed specimens—one incomplete at the posterior 
end, the other with forty-two segments—show the anterior 
unpaired process of the head (PI. II., fig. 22) developing 
to a large size; its distal end is flattened, but not 
bifid. McIntosh (1894: p. 73) remarks that none of 
Claparede’s or his own specimens showed this con- 
spicuously, and suggests that 1t might be expected later 
