aspects of the anterior end for comparison with the two 
preceding figures of Arenzcola. 
Fig. 7. Dorsal aspect. Prostomium with pair of 
tentacles, pair of much stouter palps and four eyes, the 
peristomium bearing on each side four cirri (the basal 
portions only are shown on the left), the first and second 
body segments with their parapodia. x 6. 
Fig. 8. Ventral aspect. Note prostomium with ten- 
tacles and palps, peristomium bearing mouth on anterior 
margin, the first and second body segments with their 
parapodia. The structure at the base of the palps is part 
of the peristomium forming the upper lip. x 6. 
Fig. 9. Nereis pelagica. A parapodium, from the 
74th chetigerous segment, divided distally into bilobed 
notopodiwm and neuropodium, each of which bears a 
sensory cirrus, au aciculum and a bundle of setee (jointed) 
situated in a setal sac, the lips of which are well seen in 
the neuropodium. x 20. 
Fig. 10. The seventh notopodium and the small and 
simple first right gill of the Laminarian specunen shown 
in fig. 1. Compare with fig. 19 Sab? 
Pirate II. 
Fig. 11. Three notopodial setie from a_post-larval 
specimen +35 mm. long. Most of the sete are of the type 
shown in fig. LLC (x. 800), but in each notopodium there 
is one seta of the kind shown in figs. 114, 116. (x 1,000.) 
Fig. 12. Distal fourth of a seta (75 mm. long) from 
a Laminarian specimen 250 mm. long. x 80. 
Fig. 13. A portion of same seta (from the region 
marked +) more highly magnified. On the lett the 
broad lamina, with its finely dentate margin, is shown. 
x S00. 
