POLYCHZT LARVA. 599 
Phyllodocid B.—? Hulalia—(P1. I1., figs. 8-9.) 
I have only been able to examine one specimen—a 
Nectochaeta—of this larva alive. In order to avoid 
confusion, all three stages will be first described from 
preserved specimens only, and the additional features 
seen in the one living specimen added at the end. 
The two oldest (mounted) specimens show the 
characteristic appendages of a Phyllodocid, and another 
(a Metatrochophore) is undoubtedly a younger form of 
the same species as these, although no specially Phyllo- 
docid features are visible. The remaining (mounted) 
specimen is a Trochophore, which shows a clear yellow 
pigmentation of the periphery, especially at the apical 
pole. The youngest of the three older larvae shows this 
clear yellow pigmentation in places, though not so exten- 
sively; the two Nectochaetae, like all other larval Poly- 
chaets obtained (excepting some of the Trochophores of 
the smaller species, “* Phyllodocid A’’), show no trace of it 
whatever: as, in addition, there is a general similarity of 
structure between the Metatrochophore and this Trocho- 
phore, and as the large size of the latter closely 
approximates to what would be expected of the trocho- 
phore stage of the former, it seems reasonable to refer 
them, provisionally at least, to the same species. 
[Trochophore.—tThe Trochophore thus referred 
to is roughly spherical in shape, but its apical pole 
is somewhat flattened. Its greatest diameter is 350u. 
The prototroch is strongly developed, and_ situated 
slightly above the equatorial plane. The mouth is 
surrounded by much shorter cilia. Paired anterior 
(ganglionic) and posterior (subsequently segmented) 
masses of deeply-staining tissue are present, and some- 
what more conspicuous than in the Trochophores of 
Phyllodocid A; probably each of the ganglionic masses 
