DODECACERIA CONCHARUM. 



255 



1. Dodecaceria concharum, (Ersted, 1843. Plate XCI, fig. 3; Plate 0, fig. 1 — tenth 



bristle ; PL CVII, figs. 7 and Id— hooks. 



Specific Characters. — Head more attenuated than the rest of the body, and the 

 anterior border rounded. 1 Body about one inch long, or more, slightly tapered anteriorly, 

 and more distinctly and gradually posteriorly. It is rounded throughout. Segments sixty- 

 five. Tentacles twelve, commencing on the anterior part of the second segment, and the 

 first are longer than the others, pale green or dull orange in colour, with darker pigment at 

 the tip. Body brownish-red anteriorly, greenish-yellow posteriorly. The first seven feet 

 have fascicles of capillary bristles dorsally and ventrally. The eighth has a few of the 

 characteristic bill-hook crotchets ventrally amongst the bristles, and at the tenth the 

 crotchets only are present. In the posterior region the dorsal division of the foot has a few 



nc. 

 Fig. 126. — Transverse section of the anterior third of Dodecaceria concharum. 



long capillary bristles, and short, stout, hook-like bristles bevelled at the tip — evidently 

 modified crotchets. Ventrally are a few short bristles and one or two of the bill-hook 

 crotchets. 



1822. 

 1841. 

 1843. 

 1844. 

 1851. 



1853. 

 1855. 



1861. 

 1865. 

 1867. 

 1868. 

 1873. 



Synonyms. 



Nereis sextentaculata, Delle Chiaje. Memorie, vol. iii, p. 176, Tav. xliii, fig. 16. 



„ „ idem. Descriz., vol. iii, p. 97, Tav. 105, fig. 16. 



Dodecaceria concharum, GErsted. Annul. Danica Consp., p. 44, fig. 99. 



., „ idem. Arch. f. Naturges., Bd. x, p. 109. 



„ „ Sars. Nyt Mag. f. Naturvid., Bd. vi, p. 207. 



Cirratulus „ Grube. Fam. Annel., pp. 68 and 134. 



Terebella ostrese, Daly ell. Pow. Creat., ii, p. 209, pi. xxvi, £. 10. 



Narganseta corallii, Leidy. Invert. Rhode Island, etc., p. 12 (144), pi. ii, figs. 46 — 48. 

 Heterocirrus saxicola, Grube. Arch. f. Naturges., p. 109, pi. iv, fig. 11. 

 Cirratulus concharum, Danielssen. Nyt Mag. f. Naturvid., Bd. xi, p. 52. 

 Dodecaceria concharum, Johnston. Cat. Worms Brit. Mus., p. 202, fig. xxxviii. 



j, „ Malmgren. Annul. Polych., p. 96. 



„ „ Mcintosh. Ann. Nat. Hist., ser. 4, t. ii, p. 286, pi. xx, figs. 1 — 4. 



Heterocirrus saxicola, Grube. Abh. Scldes. Gesell. (1872), p. 7 (sep. cop.). 



Of four segments conjoined, CErsted. 



