1903. MARINE FAUNA OF ZANZIBAR, 175 
The contained worms are the smallest of the species described 
here, or in (6), being slightly smaller every way than in P. elioti. 
The specific name refers to the abundance of brown colour 
found on their tentacles and fore-body, Pigmentation, except of 
the gut, is rare in the Cheetopteride. Of the other species, it is 
described in only two, viz. P. claparedi (8) and P. socialis (a): ari 
both these it is comparatively slightly developed. 
The ground-colour of the anterior region, tentacles, and para- 
podia of P. pictus is, in life, creamy white. The greater part of 
the posterior regions is, as usual, black, by reason of the pigmen- 
tation of the gut. 
On either side of the groove which runs along the upper surface 
of the larger tentacles are regularly arranged squarish blotches 
of brown, as shown in Pl. XVI. fig. 5. Brown dots are scattered 
also over the pro- and peristomium and the anterior segments of 
the fore-body. There are two dark bands with indefinite edges 
along the ventral bases of the notopodia, and a broad crescent 
across the ventral surface of the end of the region A. 
The mouth is not at all funnel-shaped, but rather slit-like, the 
two small peristomial lappets coming together from either side. 
The prostomium is large, flattened from side to side, and projects 
above the dorsal surface of the fore-body. The very slender second 
setigerous pair of tentacles lie close on either side of it, being thus 
very inconspicuous. Two elongated, but distinct, eye-spots, of a 
dark brown colour, occur one on each side of the prostomium. 
The regions A and B consist of the following numbers of 
segments in different individuals :— 
* % * 
Doren OM UG.) Sls SMe eaieye CaS 
Bese uh 9 9) 7 9) 3 8 — 
* These specimens were below the average size. 
The fourth notopodium has but one large seta of the shape 
shown in Pl. XVI. fig. 9,a. The bending of this seta is remarkable 
as occurring only in this species. Its three teeth, when seen from 
one point of view, give an explanation of Langerhans’s figure of 
the corresponding seta in P. gracilis, which is not otherwise 
intelligible. 
The other setz are all straight, and present no peculiarities 
except those of the last notopodium, which are bent, and the head 
is finely toothed (fig. 9, c). . 
The parapodia of the region B (figs. 5 & 6) are small, the 
neuropodial ridges especially so. In correspondence with this the 
uncini are very minute and delicate (03 mm. long), and their 
teeth barely visible under a 1-inch objective (fig. 9, d). The 
neuropodia do not extend far up the side of the body, and the 
space between them and the notopodial gills is not filled up by 
the triangular membranous gill-flap as in the other species (fig. 6). 
The notopodia contain two or three thin sete which do not project. 
In the region C the notopodia are reduced to little clavate 
papille, containing one seta, as in all the other species except 
