CHONE FAUVELI. 293 
from Greenland, for in lateral view the shafts are curved, constricted as they approach 
the wings, and the tip leaves the shaft at an angle, whilst it is finely tapered and bordered 
with the narrow wings. In antero-posterior view the constriction at the upper end of 
the shaft is distinct, the base of the tip (continuation of the shaft) being considerably 
broader. On the other hand, the bristles of the Greenlandic species are much more slender, 
the tips longer and more attenuate, and the wings just visible. ‘The constriction of the shaft 
below and its dilation above the commencement of the tip scarcely attract notice. They 
are obliquely striated, and have serrated edges laterally. When the tip of the shaft is broken, 
the transparent web connecting the wings is evident, and the margins of the wings are stiffened 
by an incurvation and slight thickening. There is little difference between the first tuft 
and the last except that the posterior are rather more obtuse at the tip. In transverse section 
the exterior of the bristle is hyaline, the centre granular from the fibres. On examining 
the bristle-tufts of this region with a lens, a double series of black dots appears—caused 
by the central stalk of each spatulate bristle. 
A change occurs at the ninth bristle-bundle, which is now ventral to the row of hooks, 
for all have taperimg tips with the serrate wings, and slant upward and backward. The 
succeeding tufts are equally powerful, and have the same direction till the posterior fifth 
is reached, and there the bristles gradually assume an opposite direction—that is, slant 
downward and forward. These posterior bristles are longer and smoother, present no serra- 
tions, and the terminal wings are narrower, so that the shaft is more conspicuous. The free 
portion of the bristle increases disproportionally, the shaft being little more than quarter 
the length (Plate CX XIX, fig. 6a). Further, whilst the bristles of the anterior region are 
in front of the median ring of the segment and the hooks behind it, the posterior bristles 
are more nearly in a line, though still anterior to the row of hooks. Generally speaking 
the anterior bristles have most of their shaft below the skin and a shorter tip, whilst the 
posterior have a short shaft under cover, and a long tip—conditions doubtless connected 
with their functions. 
The rows of hooks commence on the second bristled segment to the ventral side of 
the bristles, and the first seven—that is, those of the anterior region—are longer and 
more boldly marked than the succeeding, appearing like minutely dotted dark lines under 
a lens. The hooks (Plate CXXX, fig. 2b), are arranged alternately in a double row, 
but toward the ends of the row, especially ventrally, appear to form a single series. Hach 
presents a long curved, striated shaft, deeply inserted into the muscular coats, and 
tapering from the well-marked shoulder to the base (which extends even further than in 
the figure). The neck is translucent, finely striated, especially superiorly, narrowed above 
the shoulder, and again slightly dilated as it approaches the head, which has a powerful 
main fang extending from the throat at more than a right angle, and with five or more smaller 
teeth on the crown in lateral view, and they extend to the downward curve of the crown 
posteriorly. The hooks in the seven rows maintain the same structure, the posterior perhaps 
being shghtly stronger. In transverse section of the shaft of the hooks the centre is fibrous, 
and at the shoulder it is somewhat flattened and has an indentation of the fibrous area (Plate 
CXXX, fig. 2a), a condition which explains the peculiar blank always seen on one side of 
the shaft. At the ninth segment the hooks change to the dorsal side of the bristles, and 
they maintain that position to the posterior end of the body. These hooks (Plate CXXX, 
