200 POLYCIRRUS HJGMATODES. 



The body has a similar outline to that of P. aurantiacus, but the species is smaller 

 and the posterior region finely tapered, the edges being serrated by the uncinigerous 

 processes, whilst the anus has two dorsal papilla and a more prominent mid ventral 

 papilla. The surface is rounded dorsally and grooved ventrally. Anteriorly the first 

 mid-ventral shield is proportionally larger than in P. aurantiacus, and is somewhat lozenge- 

 shaped, the anterior angle being carried forward to the mouth. Behind it is a narrow 

 fillet followed by 7 pairs of conspicuous glandular scutes succeeded by a series of smaller. 

 Glandular extensions occur laterally at each setigerous process. The segments are 

 marked by narrow rings as in the former species. The colour is deep red, in others the 

 body is translucent, with a faint tinge of brick-red, and the intestine throughout is pale 

 red, but as it dilates widely during the various movements this tint is interrupted 

 by pale (dilated) areas, or the narrow reddish tube is twisted on itself in the 

 translucent coelom. In some the variegated aspect of the body is due to the bright red 

 cells (perivisceral corpuscles), which alter the tint as they roll to and fro. The ventral 

 scutes have the same reddish hue as the rest of the body. When sickly the colour 

 fades — becoming pale brownish-reel. 



The anterior setigerous processes, which commence on the second segment, appear 

 to have a slightly longer posterior papilla dorsally than in the former species, but the 

 bristles are similarly arranged in a longer and shorter series, the letter being more 

 numerous ventrally. The bristles have very narrow wings, are translucent, pale golden, 

 and in lateral view present a slight enlargement before tapering to the delicate tip, which 

 is slightly curved (Plate CXXVII, figs. 2 and 2 a). The shorter forms have a more 

 attenuate, hair-like tip, and also present a trace of an enlargement below it. The 

 posterior bristles are shorter, more slender and fewer, in number in the. small tufts. 

 Some of the bristles present a brush-like tip (Plate CXXVII, fig. 2 b), apparently 

 from friction. 



The uncinigerous processes commence about the ninth bristled segment, and the 

 hooks occur in a single row. Anteriorly the hooks (Plate CXXVII, figs. 2 c and 2 c') are 

 small, have a much shorter base than in P. aurantiacus, and the inferior outline rises into 

 a convexity behind the slender prow, while posteriorly it juts into a process. Two or three 

 teeth occur above the main fang, and a distinct process projects from the anterior outline 

 just beneath it. The depth of the base posteriorly and its abrupt slope to the prow give a 

 character to the hook. Comparatively few seem to be in each row. Posteriorly the hooks 

 are considerably smaller (Plate CXXVII, fig. 2d), but still have two teeth above the 

 main fang. The curves anteriorly and posteriorly are less defined than in front. 



Reproduction. — Mature in August (Southern). 



De St. Joseph observes that Polycirrus hxmatodes is not phosphorescent, and thus 

 differs from P. aurantiacus, so that the Polycirrus phosphoreus of Verrill, 1 which is bright 

 red or blood-red, with ova of the latter tint, is apparently another species. 



Hessle (1917) includes P. elisabethx, Mcintosh, under Wollebask's P. norvegicus, but 

 on the whole it rather falls under P. hdematodes, of which species it is probably a northern 

 variety. 



1 < Proc. U.S. National Mus./ vol. n, p. 181, 1879. 



