72 WwW. C. MCINTOSH. 
have shorter bristles. Each segment has a short tuft of cilia, 
somewhat resembling the ventral tuft in the Magelona-larva. 
The terminal segment is ring-like and bears long cilia. The 
alimentary canal is pale and wide, but constricted at each 
segment-junction. 
An older stage with from eighteen to twenty-four segments 
showed dorsal and ventral foot-papille, and a pair of rudi- 
mentary tentacles on the head, the posterior part of which is 
elevated (as in Pl. 7, fig. 7). 
When the larva reaches 24 to 3 mm., and has from thirty- 
five to fifty segments, the tentacles are longer and show an in- 
ternal cavity, and the rows of cilia are longer, though shorter 
than in the larve of Leucodore. The lips are richly ciliated, 
and a tuft of cilia occurs on each side behind the head. The 
anterior pair of eyes are blackish, as in the older larve, whereas 
the posterior pair are reddish. The foot-processes are larger 
at this stage and somewhat conical. Moreover, a brownish 
speck occurs between them, whereas in the examples at St. 
Andrews it was whitish or yellowish white. The bristles have 
the same rough aspect (from minute spikes), and the first seg- 
ment bears longer bristles than the following. In all the seg- 
ments the ventral row of cilia is present, while posteriorly is 
the anal ring of long cilia. The pale alimentary canal contains 
sea-water. The larva wriggles through the water for some 
time and then settles on the bottom. It is translucent like 
Tomopteris, the only pigment being the coloured specks on 
the sides (between the feet). 
When supplied with sea-water, development proceeded, the 
dorsal and ventral divisions of the feet from the seventh to the 
eleventh becoming longer, thicker, and with a slender tip, all 
the others remaining as before. Further, the dorsal branch 
of the foot showed reddish pigment, whereas the ventral re- 
mained pale. The opaque speck (black?) remains between 
them. By-and-by the long cilia of the lateral regions of the 
head and the anal ring disappeared. Moreover, the presence 
of the longer feet from the seventh to the eleventh segments 
was somewhat inconstant, for in one in which only thirty-five 
