356 PERCY SLADEN TRUST EXPEDITION. 
1. Chlwia fusca, McIntosh. (Plate 45. figs. 1, 2.) 
Voyage of H.M.S. ‘ Challenger,’ Report on the Annelida (McIntosh), p. 14, pl. ii. figs. 1-2, pl. i. a, 
figs. 14-15, pl. il. a, figs. 1-2. 
Several specimens of this form are contained in Mr. Gardiner’s collection. It was only 
known previously from a single specimen obtained by the ‘ Challenger’ from the 
Moluccas. The presence of the three types of setze mentioned above is the most strongly 
marked character, but there are also recognisable in the forms under examination the 
well-developed caruncle composed of rather loosely arranged vertical lamelle, the well- 
developed median tentacle exceeding the caruncle in length, the mouth whose posterior 
border is formed by the third body-segment, and the sinuous gills with their longitudinal 
axis lying outwards and backwards, which McIntosh has described in his excellent 
account. 
In colour and markings (Pl. 45. fig. 1) the Seychelles specimens show considerable 
variation from the original form. McIntosh speaks of the colour as an “ iridescent 
dusky brown,” and concentration of pigment occurred, for instance on the branchiz. 
In these there is a pale ground-colour with a couple of thin longitudinal purple stripes 
near the dorsal middle line. There is also on each side a line of segmentally repeated 
orange-coloured crescentic markings parallel and external to the purple stripes. Beneath 
each dorsal bundle of bristles is a purple ring shading off into orange, and the gills are 
pigmented, the axis being tinged with orange and the pinnze with crimson. ‘The dorsal 
cirri are a dark purple. 
The single example obtained by the ‘ Challenger ’ did not allow of a thorough examina- 
tion of the sete, many of the segments being swept bare. On looking through the 
plentiful material in this collection all three types of bifid setze recognised by McIntosh 
are found, and some information may be added as to their distribution. Throughout the 
body the slender elongate type occurs, but it is in the anterior segments alone that the 
stout kind of smooth seta occurs. Posteriorly it is replaced by McIntosh’s third type 
with a fork of a “ tuning-fork” description and serrations on the longer ramus. There 
is always, moreover, a tendency for the second type to vary toward the third, and setz 
are found even in the anterior segments, which resemble the latter type in form and 
differ only in the absence of serrations. 
The caudal appendages, which were absent in McIntosh’s specimen (vide description) 
are rather short sausage-shaped structures. Itis rather unfortunate that C. fusca should 
have been figured with a pair of long slender styles in the ‘ Challenger ’ report. 
Locality. 6 dredged in 34 fathoms, E9, and 9 in 25-80, E11. Both Amirante 
Islands. 
They were living “‘among the basal fronds of Halimeda” *: with the first batch was 
associated Notopygos gardineri, and with the second a considerable number of 
N. hispida. 
* The quotations in this and other cases are from Mr. Gardiner’s notes. 
