MYXICOLA AISTHETICA. 317 
St. Joseph, though the absence of anterior hooks leaves a margin of doubt in relation 
to the last mentioned. It is a small form, measurmg about ? inch in total length, and 
having the typical condition of the cephalic region. The branchiz are of moderate length, 
and have broader wings and less tapered tips on the distal processes of the filaments 
than in M. infundibulum. 
The anterior region seems to be short as in M. Dinandensis, which has only three 
segments, and in the specimen from Herm the long crotchets appeared to have only 
a single tooth above the main fang as in M/. wiridis. The posterior hooks came far forward, 
and in structure they differed from those of their allies, for the main fang is propor- 
tionally larger and the tooth above it is only about half its length, and thus contrasts 
with the condition in other forms. The basal region has a nearly straight inferior border, 
to which the prow curves downward. 
Whether this is an example with the anterior region in course of reproduction or a 
variety is uncertain, but its features are worthy of note. It may be a young variety of 
M. viridis, since the hooks in each closely approach in structure. 
2. MyxIcoLaA MSTHETICA, Claparéde, 1870. Plate CXXX, figs. 5 and 5a—anterior and 
posterior hooks; Plate CX XXII, fig. 8—anterior bristle. 
Specific Characters.—Cephalic plate similar to that of M. infundibulum. Branchiee' 8 
in each fan, the tips less attenuate and more broadly webbed than in the form mentioned ; 
tentacles short and almost semilunar. Body about an inch in length, nearly cylindrical, 
tapered posteriorly to the vent. Dorsum has hook-like bands of dark pigment transversely 
arranged on each side, leaving the centre bare. ‘Two bands of eyes occur on the first 
segment, whilst laterally are two reddish-violet eyes in each segment. The terminal 
segment has a band of six or seven eyes within its border. Several statocysts are found 
in the second segment containing spherical statoliths. Colour yellowish-white. First 
segment achetous ; the three following having dorsally pale winged bristles, and ventrally 
peculiar long crotchets, even more like those of an Oligochet than in the typical form. 
Thereafter the winged bristles are ventral and avicular hooks dorsal. 
Mucous tubes on algze. 
SYNONYMS. 
1870. Leptochone xsthetica, Claparéde. Suppl. Annél. Neap., p. 149, pl. xiv, fig. 1. 
1875. Myzicola M Marion. Rev. Sci. nat., t. iv, pp. 809 and 310. 
1893. 5 ae Lo Bianco. Atti R. Accad. Sc. Nap., vol. v, no. 11, p. 80. 
1898. . . Soulier. Soc. Languedoc Montpell., t. u, 2 fase., p. 343. 
1902. A - idem. Annél Cette, p. 25, fig. 6a-e; Trav. d’Instit. Zool. de Montpellier, 
2 sér.. Mém. 10 and 15, pl. ii, fig. 20; pls. iv, v, ix and x. 
1907. 5 x idem. Acad. se. Montpel., 2° sér., t. i, p. 133. 
1915. a (Leptochone) xsthetica, Allen. Journ. M. B. A., vol. x, p. 642, 
ION, a zsthetica, Rioja. Anél. Polig. Cantab., p. 72. 
1 Claparéde gives the branchiz a greenish tint. 
