MYXICOLA VIRIDIS. 319 
3. MyxicoLa viripis, Milne Edwards, 1836—49._ Plate CXVI, figs. 1 and la—body and 
branchie; Plate CX XI, fig. 4—body ; Plate CXXX, figs. 6, 6a and 6b—bristle and hooks. 
Specific Characters.—Cephalic region similar to that of M. infundibulum. Branchize form 
a green spiral mass in repose, and a double fan in expansion of nine or ten or even fourteen 
filaments, each with a chordoid axis, and a strap-like terminal process, which abruptly tapers 
to a short terminal filament. Slightly banded with seven bars. Body of about forty-seven 
segments—eight anterior and thirty-nine posterior, tapered posteriorly to an anal papilla. 
Colour rich green, the central intestine being darker. Anterior bristles most conspicuous, 
and the first pair is directed forward and outward. Bristles slender, translucent, with finely 
tapered tips and narrow wings. The posterior bristles are smaller, and many present a 
curvature at the commencement of the tip. Anterior hooks in groups of five or six, long, 
f-shaped. Main fang leaves the long and nearly straight neck almost at a right angle, and 
is short and sharp. A single prominent tooth occurs on the crown above it. Typical posterior 
hook minute, with a long, sharp main fang, and a tooth almost as long above it. Posterior 
outline nearly straight ; short base directed forward. 
SYNONYMs. 
1836—49. Sabella @ sang vert (Milne-Edwards), Cuvier. Illust. Hdit., pl. 1c, fig. 2.1 
1843-53. ? Amphitrite viridis, Chenu. Illust. Conch., 11° livr., pl. vi, fig. 1. 
1874. Sabella viridis, McIntosh. Ann. Nat. Hist., ser. 4, vol. xiv, p. 206. 
1875. 3 » idem. Invert. and Fishes St. Andrews, p. 130. 
Habitat—In the mud of a recess of a mass of Fulograna from the neighbourhood of the 
Bell Rock, St. Andrews Bay, 1863. 
The cephalic region seems to agree with that of M. infundibulum both in the absence 
of a collar and in other respects. The branchiz form a rich green spiral mass in repose 
(Plate CXVI, fig. 1a), a position often assumed in its sheath under examination, but when 
it protrudes the anterior end the branchiz spread out as a double fan (Plate CXVI, fig. 1) 
of nine or ten filaments, which have a chordoid axis and a terminal process, which differs 
from the tapering elongated one of M. infundibulum in maintaining its strap-like breadth 
till near the tip, where a short tapered region occurs. | 
Body capable of considerable elongation, and the total number of segments is about 
forty-seven—eight anterior and thirty-nine posterior. A well-marked papilla at the anus 
terminates the body posteriorly. ‘The colour is a rich green, the central intestine being 
darker. 
The first pair of bristle tufts has a different direction from those which follow—being 
directed obliquely forward and outward. ‘The anterior bristles are the most conspicuous 
indeed in a specimen so minute the posterior bristles at first escape notice. The typical 
anterior bristle (Plate CX XX, fig. 6) has a slender translucent shaft, a finely tapered tip 
and narrow wings. The posterior bristles are more minute and the wings less distinct. 
Many present a curvature at the commencement of the tip. 
1 “Dans cette espéce le sang, au lieu d’étre rouge comme chez la plupart des Annelides ou a peu 
prés incolore comme chez les Aphrodites, etc., est’ de couleur verte.” 
