188 SYLLIS ARMILLARIS. 



stolons (schizogamy). Malaquin divides them into two primary gronps according to the 

 presence or absence of a branchial appendage, and he separates the genera by the armature 

 of the proboscis. Ventricule (stomach) well-developed, with lateral T-shaped pouches. 

 Apparently only one genus of this group occurs in Britain. 



Genus LIV. — Syllis, Savigny, 1820. 



Head with three tentacles ; two pairs of tentacular cirri — all moniliform. Palpi 

 separate throughout. Body more or less elongate, with distinct segments. Opening of 

 the pharynx (proboscis) only with papilhe ; armature a single anterior tooth dorsally. 

 Proventriculus short, two T-shaped glands behind. Feet with moniliform dorsal and 

 filiform or pinniform ventral cirri. Falcate bristles with a short terminal piece ending in 

 a single hook, or with simple bristles partially, rarely throughout. Tail with two 

 elongated cirri. 



Reproduction normal, or by alternation of generations. Sexual individuals furnished 

 only with two tentacles and devoid of tentacular cirri. Sexes similar. 



1. Syllis armillaris (Muller), (Ersted, 1842-3. Plate LX, fig. 1— head, fig. 2, Ioida— 

 head; Plate LXX, fig. 14— foot; Plate LXXIX, figs. 8, 8 a, 9, and 9 a— bristles. 



Specific Characters. — Head rounded, about as long as broad, four reddish eyes obliquely 

 placed, the anterior pair being the wider apart. Palpi ovate. Median and lateral tentacles 

 moniliform. Body two or three inches long, slightly diminished in front and tapering to a 

 lanceolate point posteriorly between the caudal cirri. Straw-yellow, streaked transversely 

 by two lateral bars and a central bar of greyish brown in each segment, so that anteriorly 

 there are three rows of dark touches. Proboscis with a single conical tooth, and ten papillse 

 on its margin. 1 The foot has dorsally a moniliform cirrus of 10 — 12 segments, barely 

 equalling the diameter of the body, and carried alternately horizontal and erect. 

 Setigerous region bluntly conical — bearing spines and a group of strong bristles, which in 

 the anterior segments have a short spinous terminal piece with a simple hook at the tip, 

 which points upward in the normal position of the foot. Ventral cirrus lanceolate. 



Synonyms. 



1776. Nereis armillaris, 0. F. Muller. Zool. Dan. Prodr., p. 217. 



1780. „ „ 0. Fabricius. Fauna Grroeul., p. 294. 



1791. „ „ G-melin. Linn. Syst. Nat., i, pt. vi, p. 3115. 



1800. Die geperlte Nereide, O. F. Muller. Xaturges. einiger Wurm-Arten, p. 150,, Tab. ix, f. 1 — 5. 



1806. Nereis armillaris, Turton. Linn. Syst. Nat., iv, p. 86. 



1820. Lycastis armillaris, Savigny. Syst. Annel., p. 45, pi. iv, f. 3. 



1824. Nereis armillaris, Bruguiere. Tabl. Encycl. Meth., Vers, I, p. 134, Tab. Iv, f. 13 — 17. 



1825. „ „ De Blainville. Diet. Sc. Nat., xxxiv, p. 436, pi. xiv, f. 2. 

 1828. Nereisyllis monilaris (and ornata), idem. Ibid., p. 473, t. lvii. 



1 Vide body-wall in Fig. 50, p. 139. 



