DASYCHONE ARGUS. 273 
Lo Bianco* (1893) mentions that Amphiglena, like certain species of Myzxicola, abandons 
its temporary membranous tube after a longer or shorter period. 
Nusbaum’ (1905) gives an elaborate account of the regeneration of the anterior and 
posterior ends and the various tissues in this species—which he examined at Naples along 
with Nerine cirratulus. The process of regeneration of the branchie resembles that of the 
development of the organs in the young form. 
Genus CLXX.—DasycuHonge,’ Sars, 1861. 
? Clymeneis, H. Rathke, 1842; Branchiomma %, Kolliker, 1858. 
Cephalic region with a well-developed though rather thin collar, which is folded and split 
dorsally, and has a shallow notch on each side ventrally, the central region showing a thin 
reflected ventral lamella of a triangular shape on each side of the middle line, somewhat 
like that of Sabella penicillus. Body rather short, slightly rounded dorsally, flattened ventrally, 
and consisting of two regions. It tapers somewhat abruptly to a short tail with a median 
bilobed anus. No anterior dorsal furrow, but ventrally it commences on the left in the 
fissure between the eighth and ninth bristled segments, reaches the middle line at the posterior 
part of the ninth and continues to the anus. A black pigment spot between the setigerous 
process and the row of hooks throughout. Branchiz forming a subconvolute fan on each 
side, the tips of the organs ending in a delicate filament of moderate length, bordered by a 
web at the base, and having a series of external appendages, and often pairs of ocular specks. 
Tentacles two; a third or a fourth the length of the branchie. Anterior region of eight 
bristled segments (the first bristles being on the second) with the accompanying uncinigerous 
rows ventrally ; posterior region with the bristles ventral and the hooks dorsal. Bristles 
of two kinds, a longer dorsal series with more attenuate winged tips, and a ventral series 
with broader wings. Tubicolar. 
1, DASYCHONE ARGUS, Sa7s, 1861. Plate CXII, fig. 6—body ; Plate CXIIIa, fig. 5—pale 
variety ; Plate CXX, fig. 14—ventral view of the anterior region; Plate CXXI, 
figs. 1—ld—hbody, branchia, ova; Plate CX XIX, figs. 1—1 f—bristles and hooks. 
Specific Characters —Cephalic plate (on removal of the branchize) shows on the truncated 
surface, at the dorsal inflection, two small folds from which a pear-shaped area passes ventrally 
to end in the oral ridge, the margin being formed by the collar, which has a lateral notch 
separating the reflected and somewhat triangular ventral lamelle from the rest of the rim 
whilst a wider gap in the middle separates them from each other. The individual elements 
of the fused bases of the twelve to eighteen or more branchie are marked by a reddish 
pigment-speck interfilamentar in position. From each half of the base (semicircle) the 
finely coloured filaments project freely, and end in short processes, at the base of which 
the pimne somewhat suddenly cease. Along the outer edge of each filament a series 
1 “Atti Accad. Sci. Fisiche e Mat.,’ vol. v, p. 2 (sep. copy). 
2 «Zeitschr. f. wiss. Zool.,’ Bd. xxix, p. 222, taf. xi1i—xvi, and text-figs. 
3 daous, hairy, and xoa, funnel. 
