FLABELLIGERA AFFINIS. 107 



The genus was first characterised by Otto (1820) under the name of Siphostoma, but 

 this term had formerly been employed by Raphinesque in 1810 for a genus of Lopho- 

 branchs. After Sars had given the above title Dujardin in 1838 applied the term 

 Ohlorzema to replace Otto's name. Claparede holds that Otto's name, Siphostoma, 

 corrected to Siphonostoma should stand. 



Body enveloped in mucus; long cuticular papillse ; setae of the anterior region turned 

 forward so as to form a cephalic funnel, with a large number of branchial filaments on 

 each side of the head. 



Delle Chiaje, 1 in 1841, described Siphono stoma as having a free body, attenuated 

 posteriorly, covered with mucous follicles, having long opposing bristles in front, pro- 

 tecting the branchial cirri, a group of tentacles in front, and a uniramous foot. 



1. Flabelligera affinis, Sars, 1851. Plate LXXXIX, fig. 2; Plate XOVI, fig. 10— 



papillae; Plate CIV, figs. 7 — 7b — bristles. 



Specific Characters. — Body about 3 inches in length, tapered a little anteriorly to the 

 base of the bristle-fan, and much more posteriorly, somewhat flattened, especially 

 ventrally. Segments, thirty to forty-five. Enveloped in a transparent gelatinous 

 investment to the tips of the bristles, and with a dense series of long papillae with urn- 

 like and clavate tips. Colour brownish-green anteriorly, or greenish with a central streak 

 of reddish-brown, then pale green in the middle line posteriorly with the same margin as 

 in front. Groups of white grains occur in every segment throughout the greater part of 

 the body. Branchiae, twenty to twenty-five, green ; palpi pale yellow or orange. Mouth 

 with a dark brown pigment-ring. Tongue-shaped process passes from the mouth dorsally 

 between the bristle-fans. Dorsal and ventral bristles of the first set form a vertical fan 

 on each side. They are directed forward, as also are the dorsals of the second and third. 

 All are articulated. The ventral setigerous process of the second set carries a single long 

 hook with a ringed shaft, which dilates a little at the articulation ; the terminal claw, 

 which is borne at a large angle to the shaft, has a slight median dilatation (variable), and 

 ends in a sharply-curved brown tip. 



Synonyms. 



1829. Flabelligera affinis, Sars. Bidrag til Soedyr. Nat., i, p. 31, Tab. 3, f. 16. 

 1835. „ „ idem. Beskriv. og Iagtt., p. 47. 



1839. Chlorsema Edwardsii, Dujardin. Ann. Sc. nat., 2 e ser., t. xi, p. 288, pi. vii, figs. 1 — 5. 



1840. Siphonostomum papillosum, Grube. Actin. Echin. u. Wurm., p. 68. 



1841. ? Siphonostoma diplochiatos, Delle Chiaje. Desciiz., vol. iii, p. 77, Tav. 99, f. 8. 



1843. Siphonostomum vaginiferum, H. Rathke. Nova Acta Acad. Leop.-Car., xx ; p. 211, Tab. xi, 



f. 3—10. 

 „ Siphonostoma uncinata, M. Edwards. Cuvier's Regne Anim., Disciples Edit., AnneL, p. 27, 



Tab. 6, f . 4—4 a. 



1844. Chlorsema Edwardsii, OErsted. Reg. Mar., p. 79. 



1849. Siphonostoma vaginiferum, Leuckart. Arch. f. Naturges, Bd. xv, p. 164. 

 „ Chlorsema Dujardini, De Quatrefages. Ann. Sc. nat., 3 e ser., t. xii, p. 282, pi. ix, figs. 1 — 9 



(young). 



1 ( Descriz./ vol. iii, p. 74. 



