MYXICOLA INFUNDIBULUM. 315 
the Sabellids (Claparéde). This author holds that a contractile sinus envelopes the intestine 
and he is probably right. Contrary to the view of De Quatrefages, Claparéde states that 
the nerve-cords, double in front, are not separated behind, but form a single cord with a 
large neural canal (his fibre tubulaire), and in certain sections that canal has a larger area 
than the nerve-tissue, which would seem to show that the term neural canal (1879) is not 
out of place. In this connection it would appear to be a peculiar “ giant fibre,’ which 
begins as a small tube in front and gradually dilates in its course posteriorly into a large 
canal. 
The anterior region has eight tufts of bristles, which are of uniform structure (Plate 
CXXX, fig. 4), viz., long, straight, slender, cylindrical shafts and finely tapered, though rather 
short, tips slightly bent backward, and with narrow wings. In rear of the fascicles of bristles 
Claparéde (1870) mentions the occurrence of a minute ocular spot—formed of a crystalline 
body surrounded by pigment. ‘This has not been observed in the preparations. Posteriorly 
the translucent bristles (Plate CX XX, fig. 4a) are both more minute and more slender, and 
the shafts are tapered toward the tip, which has a:curvature as in front, and a trace of a 
wing on each side. 
The anterior region ventrally has groups of about eight long crotchets, which in general 
outline somewhat resemble those of Oligochets. The shaft is long, gently curved, tapered 
inferiorly, dilating at its distal third into an indistinct shoulder, from which it is gently 
diminished to the throat below the main fang. The neck is stout and nearly straight, and 
the main fang, which arises at a wide angle to the neck, is blunt, whilst on the crown, which 
slopes downward in lateral view, are a few small teeth. Under pressure the hook often 
lies so as to give an antero-posterior outline (Plate CX XX, fig. 46), which is hastate, a con- 
striction occurring behind the great fang, from which a gradual enlargement takes place to 
the shoulder, beneath which it again tapers to the base. The usually acute Claparéde had 
overlooked these organs. The terminal hook of the row shows a more simple form—without 
spikes in the crown. ‘The posterior hooks (Plate CX XX, fig. 4c) are large and avicular, 
and identical with the type as figured by Malmeren. They have a base much produced in 
front, the anterior outline of the neck curving from the main fang in a convex manner 
downward to a blunt prow, the inferior outline being slightly concave, as also is the 
posterior outline. The main fang is long and sharp, and above it is a comparatively large 
spike. The forward projection of the prow approaches that of the Polycirrids, but the great 
size of the secondary tooth differs. 
Reproduction.—Claparéde (1870) figures both sperms and ova, but he does not allude 
to the month in which they occur. 
The figure of this species in Montagu’s MS. volume (1808) in the Linnean Society is an 
exquisite picture from life, and worthy of the experienced touch of his niece, Miss D’Orville. 
Tube.—Montagu described the tube as entirely gelatinous, greenish on the surface, 
though ordinarily marked by the particles of the ground it inhabits. It is secreted in various 
hyaline strata, but, not as Claparéde thought, by the segmental organs opening by the single 
aperture on the dorsum anteriorly. He further thought that the cilia on the exterior of 
the branchial web had an important influence on the distribution of the secretion for the 
tube, which, Dalyell stated, was once and a half the diameter of the body, and exceeded 
its length. 
i 210 
