FLABELLIGERA AFFINIS. Ill 



edge of the collar marks the separation between the dorsal and ventral divisions. These 

 frontal bristles (Plate CIV, fig. 7) are pale brownish by transmitted light, long, slender, 

 tapering, with moderate joints which become longer toward the tip and which De St. 

 Joseph likens to Confervae. They vary considerably in strength, the most robust being 

 those in an example from the ' Valorous ' in 1875. Much of the shaft inserted in the 

 tissues is devoid of segmentation. 



The second set of bristles inaugurates those characteristic of the rest of the body, 

 but the dorsal of this and the next series or two have a tendency to a forward direction, 

 as also have the ventral hooks. These bristles are, on the whole, stronger than the 

 frontal, and the lines of segmentation are much closer. They are enveloped in the 

 milky membrane and its long-stalked papillae with the urn-shaped tips almost to their 

 extremities, and there are also many of the clavate papillae. These bristles in ordinary 

 preparations thus extend from the sides, generally nearly straight outward, or with a 

 slight obliquity backward, enveloped in the gelatinous coating, and with the tips of the 

 long papillae projecting around. Minute particles of mud and sand-grains are thickly 

 dotted on the pyramid thus formed. The enormous number of these organs indicates 

 their importance in the economy of the species. Vent-rally a single long, flattened hook 

 (Plate CIV, fig. 7 a) projects forward and outward from a conical papilla, the shaft being 

 deeply inserted in the tissues along with a reserve-hook and a group of finely tapered 

 bristles, mostly without any distinct trace of transverse articulations, though a few show 

 very faint transverse lines in the distal third. These bristles appear to vary in number 

 — from six to twelve. As De St. Joseph 1 describes and figures them distinctly articulated 

 considerable variation must occur. The British examples thus differ, though the faint 

 indications of transverse striae are noteworthy in this respect. The shaft is closely- 

 ringed at the base, then some increasingly wider segments (four to five) occur, 

 followed by narrow segments to the bare space below the hook at the tip. The end 

 of the shaft dilates a little at the articulation of the hook and has oblique striae internally. 

 From the articulation the hook extends upward and slightly inward (at a large angle to 

 the shaft) to a median dilatation, which varies in specimens from different localities, and 

 then tapers to the sharply-curved brown tip, which De St. Joseph likens to the horn of a 

 chamois (Plate CIV, fig. 7 a). It is obliquely striated internally almost to the tip. Like 

 the dorsal bristles it is surrounded by many of the long urn-shaped papillae distally, and 

 various clavate forms proximally — all with the thread-like pedicles. The row of these 

 glittering golden hooks with their brown tips stretches along each side ventrally, a 

 single hook, as a rule, projecting from each foot, though occasionally two occur. They 

 are smaller toward the tail, but do not differ in structure, or in the presence of a single 

 reserve-hook, and the group of simple tapering bristles supporting the shaft of the main 

 hook in the tissues ; nor do the papillae undergo any change of note. For comparison 

 a hook of 8. diplochaitos from Naples is shown in Plate CIV, fig. 2. The hooks are 

 coated with a fine transparent gelatinous secretion almost to the tip. In large examples 

 from Greenland both the shaft and the tip of the hook are of a deep brov :, and opaque 

 under the microscope, but their structure is similar. The same may be said of the dorsal 

 fascicle of simple tapering, closely -ringed bristles and their papillae. Looking generally 



1 Ann. Sc. nat., ser. 7, t. xvii, p. 98, pi. v, fig. 122, 



