490 CHATOZONE ALATA. 
blade-like tips finely tapered at the extremity, five being fully developed. About the twentieth 
foot the dorsal bristles are shorter but retain the same character, and by-and-by hooks 
appear in this division. In the ventral division they are at first accompanied by a bristle— 
indeed, occasionally a bristle is found in the dorsal division with the hooks! posteriorly. 
The hooks thus correspond with those of Cirratulus, and differ from Keferstein’s species 
or any allied form with the bifid hooks.” 
T am indebted to Mr. Southern, who has specially worked at the Cirratulids, for drawing 
my attention to the ambiguity of the title in the Monograph. It had escaped observation. 
A reference to the figure of the hook in the joe will show that it cannot be 
confounded with Keferstein’s species. 
CHATOZONE ALATA, Southern, 1914. Plate CXX XVI, fig. 15—hook. 
Specific Characters.—Head conical; a pair of dark, deeply-imbedded eyes. Tentacles 
large, each accompanied by a lateral cirrus. Body slender, 10—12 mm. long, and having 
110 segments, tapering at each end, especially posteriorly. Capillary bristles in all the 
dorsal tufts, the longer cylindrical, without flattening of the tips, shorter with flattened 
tips. Capillary bristles also occur in all the ventral tufts. Hooks appear in the twenty- 
first setigerous segment, and they are present in all the ventral divisions. They are bifid 
and boldly curved, as well as winged. 
SYNONYM. 
1914. Chetozone alata, Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 112, pl. xu, fig. 27a—d. 
Habitat.—Blacksod Bay, in Laminarian roots, and at the surface in Ballinakill Harbour 
at night. 
The head is conical, with two dark eyes deeply imbedded on the dorsum of the head, 
probably on the brain (Southern). Dorsal tentacles large, reaching 2 mm. in length. 
Body slender, uniform in width, tapermg a little at each end, especially posteriorly. 
Segments 100 to 110. Dorsal tentacles large, attaining a length of 2 mm., arising in front 
of the first setigerous segment, each accompanied by a lateral cirrus. Capillary bristles 
are present in all the dorsal tufts ; the longer ones being slender and cylindrical, with tapered 
tips, the shorter with flattened blades and thin along one edge. Hooks appear dorsally 
on the twenty-first bristled segment. The number of the capillary bristles decreases 
posteriorly, only one occurring in the segments near the tail. Hooks (Plate CXXXVI, 
fig. 15) are present in all the ventral divisions, and anteriorly two very slender capillary 
bristles accompany them. ‘They are bifid and boldly curved, with a shoulder where they pierce 
the skin ; the distal region has a narrow wing (hood), which appears like a margin posteriorly, 
and the shaft is slightly striated. They increase in size posteriorly, and the slender capillary 
bristles accompanying them are often absent. The number of both hooks and bristles 
diminishes posteriorly. All the examples were immature. 
Southern, from whose description much of the foregoing has been taken, considers 
Ht Worl, yall, iy, infer, I). 
2 Tbid., pl. ev, fig. 18. 
