430 EHTEONE DEPRESSA. 
The feet form an even series along each side, the typical foot (Plate CX XXIV, fig. 7b) 
having dorsally an ovate-rotundate lamella, which varies a little in the posterior region—that 
is, becomes more elongate and therefore more conical. The cirrophore supporting it anteriorly 
is short and broad, the base of the cirrus being constricted in the posterior segments as it 
approaches it, whereas in the anterior segments the low broad cone formed by the cirrus 
shows this less prominently. The distal extremity forms a blunt cone. This cirrus, as in 
one or two other species of the genus, 1s proportionally large in a lateral view of the foot, 
its cirrophore occupying about half the vertical diameter of the foot, and it extends distally 
much beyond the other divisions. The setigerous process is bluntly conical, the tip beimg 
double, with a bite in the middle, and the bristle-tuft is supported by a pale spine, the tip 
of which does not project beyond the surface, though it almost touches it. The bristles 
(Plate CX XXIV, figs. 7c and 7d) are translucent, with a distal curvature of the shaft, and forma 
broad fan anteriorly, with the convexity of the shaft directed upward. The terminal piece is 
perhaps slightly longer than in Eteone prcta, and forms a translucent tapering serrated blade. 
The shaft is dilated at its termination above the curvature, and carries a long tapering spur, 
the point of which curves toward the serrated or upper border of the terminal blade ; and 
on the same side (that is, with the serrated edge of the blade to the left) is a shorter spur 
and a series of diminishing serrations on the free edge below it. The bristle thus differs 
from that of Hteone picta, especially in the proportionally longer hook at the end of the shaft 
and the more coarsely spinous edge below the base of the larger process. In HL. picta the 
large hook is shorter, stronger, and more boldly curved, and the lateral hook smaller. In 
EF. arctica the great hook is likewise shorter and stouter. In #. lentigera the comparatively 
small though stout main hook is only a little larger than the secondary. In H. spetsbergensis 
the secondary hook is long and sharp and runs parallel to the larger hook, which is more or 
less straight. In the posterior region of the body both spines are well developed, and some 
have a tendency to curve at the tip. In HL. pusilla the disproportion between the two hooks 
or spines is great, the smaller, however, being slender and sharp. In some, small spines 
abut on the larger toward the dorsal edge of the terminal blade—that is, the side opposite 
the serrated edge. The blade, moreover, is perhaps more distinctly bellied inferiorly. 
The ventral cirrus anteriorly has the shape of a truncated cone, the tip of which projects 
beyond the setigerous lobe. In the posterior third this cirrus diminishes in bull and its 
tip is nearly in a line with the setigerous process, its ventral outline presenting a swelling 
or hump—apparently an indication of its approach to the fused cirrophore. Toward the 
tip of the tail, again, both the setigerous lobe and the ventral cirrus have diminished in bulk, 
the latter especially being longer and more slender, and its tip often projects beyond that 
of the setigerous lobe, the bristles in which are fewer and shorter. 
This form generally resembles Hteone depressa, Malmgren, and especially in the structure 
of the feet and bristles, but it differs in the presence of the “ boss ” or tentacle at the posterior 
border of the prostomium. If the various authors who have examined it, however, had 
only seen spirit-preparations, it 1s possible that 1t may have been overlooked. 
I am indebted to Mr. Arnold Watson for his courtesy, as on many other occasions, in 
forwarding the example, and for his notes and sketches of the living form. 
Théel (1879), in a brief note, states that the head differs from Malmeren’s outline, and 
he gives a corrected figure. 
