360 PERCY SLADEN TRUST EXPEDITION. 
the length of the caruncle. The lateral tentacles and palps are rather shorter 
than the median tentacle. There are prominent oral lips, and generally the first 
three body-segments form the buccal segments. The branchize commence on the sixth 
segment and are short arborescent tufts mostly destitute of pigment, outer and inner 
divisions being recognisable. The main branches divide pinnately into short terminal 
twigs. The branchial cirrus is stout, of uniform thickness throughout, and of a 
deep purple colour, as is the basal part of the long external cirrus. The former 
greatly exceeds the branchia in height. 
Throughout the body a single type of seta is found, bifurcate with the rami rather 
widely diverging and ending in sharp points. But while the dorsal sete are found 
to be smooth throughout, the ventral setze are noticeably serrate in the first few 
segments only, and smooth posteriorly. The most typical kind of serrate seta is 
shown (PI. 46. fig. 3) possessing three serrations on the inside of the longer ramus and 
sometimes (PI. 46. fig. 4) a single serration on the outer side. In most of the examples 
examined the triserrate setze were confined to the first four segments; setee with only 
two serrations were found in the sixth and seventh, and occasional uniserrate sete 
in a few of the succeeding segments. Subsequently all the bristles were smooth. 
The anus is dorsal and found on the 21st segment. The body is terminated by short 
club-like appendages. 
Locality. Amirante Is., E 11, 25-80 fathoms, 18 specimens associated with Chleia 
fusca, found in “pores and cavities in the coral rubble.” Saya de Malhas, C 15, 
55 fathoms, a specimen with Nereids, and a second example in which the purple 
coloration was obscured by the development of brown pigment throughout. 
6. Notopygos variabilis, sp.n. (Plate 45. fig. 9.) 
Measurements. A specimen with 31 segments was 45 min. long. 
9? 99 dl 3 99 55 bh) 3 
Another ”° 29 be) 9° 27 35 3° 
29 bb) 30 33 33 25 99 ” 
In shape this worm agrees closely with NV. labiatus as figured by McIntosh, being 
fusiform and showing in section a flat dorsum and rounded ventral surface. The 
dorsum is sometimes ornamented, a trapezoidal depression occurring in the anterior 
part of each segment. In individuals which retain some of their natural colouring 
a pattern of orange spots may be seen, so arranged on the dorsal surface as to give 
a chessboard effect. The appearance of the spirit-specimens gives the idea that the 
living worms are highly variable in colour and markings. While the majority of 
specimens appear almost unpigmented, three examples are coloured dark red or 
purple on both upper and lower surfaces. The caruncle extends back to the posterior 
margin of the fifth segment and is actually attached to the first four. The median 
crests and lateral wings consist, as in NV. hispida, of transverse folds laxly arranged. 
While the wings end at the posterior border of the head, the crest extends on to and 
beyond the head, the median part of which is completely hidden (Pl. 45. fig. 9). Though 
a similar extension of the caruncle may be noticed in other species (e. g. in NV. gardineri 
