STYLARIOIDES ARENOSA. 99 



8. glauca, yet the bristles are distinctly shorter and paler. The entire surface is closely 

 beset with sand-grains so that to the touch it resembles a hard sandy tube. The papillae 

 seem to be more or less cylindrical with a clay ate tip, but they exhibit no evident 

 arrangement in rows as in Mr. Webster's American form. The anus is situated in the 

 centre of the somewhat blunt tail. 



As mentioned by Mr. Webster, the bristles of the first five segments point forward, 

 but the first three are most conspicuous. The first set is the longest, and its bristles are 

 densely coated with various growths such as thecate Infusoria, algas, mud and fragments 

 of bristles. The ventral are a little shorter than the dorsal. Though pale by reflected light 

 these bristles are brownish by transmitted light, taper to a very delicate hair-like tip, and 

 have a series of articulations which are closer at the base, longer in the diminishing tip (Plate 

 CIV, figs. 6 and 6', 6 b, G b'). The ventral of the second series are considerably shorter, have 

 a dorsal curve, and taper to a less delicate though simple tip which is slightly hooked. The 

 ventral of the third series (Webster says fourth) consist of three bristles curved at the tip 

 and bifid, the tips indeed resembling those of Sigalion and Sthenelais. The terminal 

 segment (Plate CIV, fig. 6 c) is about three or four times as long as the adjoining, and 

 ends in a hook, with a secondary process in the form of a fixed band beneath (that is in 

 the concavity). Whilst only three project externally seven occur in the tissues, but four 

 are imperfectly developed. The bases of these bristles form an even row. Of the three 

 projecting externally two are larger and more opaque (brownish), have short segments 

 throughout their lower half, longer segments in their distal half, which is curved. The 

 third bristle is considerably shorter, more translucent, and has long segments throughout 

 its free portion, short segments occurring at its base — inserted in the tissues. The latter 

 apparently represents a developing bristle. The dorsal bristles project upward and 

 inward in a series of short fans, continue to the posterior end of the body and are of a 

 resplendent pale hue, and the tips have a tendency to curve forward. The ventral bristles 

 from the third backward present a gradual modification into stout hooks with bifid tips. 

 Thus at the tenth these processes retain a bristle-like appearance, with long joints which, 

 however, become shorter toward the tip, the latter tapering to a long terminal joint with 

 a hook and a secondary process differentiated at its free edge, viz. a thickened rim, but 

 the whole is bound to the concavity of the hook. At the twentieth foot a similar condition 

 exists both as regards the bristle-like stem of the appendage, the shortening of the joints 

 toward the tip, and the longer terminal joint with the hook, as well as the fixed secondary 

 process beneath with the marginal differentiation, the whole having the aspect of a 

 Polyzoan avicularian. The hook gradually becomes shorter, broader and stouter, the 

 articulations more closely arranged, and between the fortieth and fiftieth feet (Plate CIV, 

 fig. 6 d) the secondary process has in some lost its web, so that the thickened edge forms 

 as it were the mandible below the hooked beak. Toward the tip of the tail the secondary 

 process of the now short hook often disappears, and the terminal hook is considerably 

 abraded. The hook is still flattened, and has oblique strias below the translucent tip. 

 The articulations are also very closely arranged. 



It is interesting that a similar form should have been procured at sites so widely 

 separated by the Atlantic, yet there is some doubt as regards specific identity both on 

 account of the fewness of the branchiae and other features in the British form. 



