POLYCH^ETOUS ANNELIDS OF THE HAWAIIAN ISLANDS. 
1177 
corresponds to this. It is altogether probable that the difference in number of branchiae is due to a 
loss of some, especially in the second and third rows. 
Setae begin on third somite, and extend through at least 30 somites; are rather short, apex with 
narrow, very faintly striated wing on either side. Uncini begin on somite 5, and there is only one 
row in each torus. Uncinus with two smaller hooks apical to large fang (fig. 85). A protrusion on 
the convex surface gives the uncinus a characteristic 1 1 hunch-back ’ ’ appearance. Basal portion with a 
small knob. 
The body was distended with eggs. Diameter of head, 4 mm.; of thorax, 6 mm. Length of 
thorax about 15 mm. 
Collected at station 4101, on bottom of coral sand, shells, and foraminifera, in 143 to 122 fathoms. 
Type no. 5226, U. S. National Museum. 
Thelepus sp. 
A single much mutilated specimen, all tentacles having been lost. Gills finger-shaped processes 
on second, third, and fourth somites. Those of second longest, about 12 in number. Those on 
third about equal to these in number, but scarcely more than two-thirds as long. Those on fourth 
fewer in number, bearing in length about the same proportion to those on somite 3, as do these 
latter to those on somite 2. 
Setfe on thorax slender, with curved ends. A number of irregular serrations, looking like sand 
deposits, appear on curved portions of setse. Uncini with short basal portion less than half the 
length of the great fang, terminated by a small, rounded “button.” Great fang long, curved. On 
either side of apex a smaller fang, about one-sixth length of larger one. Between these small fangs a 
median elevation, like the basal portion of the fang in shape but without the sharp point. 
Collected at station 4551, vicinity of Monterey Bay, California. 
Genus AMPHITRITE Muller. 
Amphitrite sp. 
Fragments of an Amphitrite, too much injured for identification, were collected from station 3865, 
256-283 fathoms, on a bottom of fine volcanic sand and rock. They were contained in a membranous 
tube thickly covered on the outside by foraminifera shells. 
Genus TEREBELLIDES. 
Terebellides tentacula, new species. 
Length of head and setigerous somites, 9 mm.; width, 1.5 mm. Very considerable differences are, 
however, to be noted in these measurements, due to different degrees of expansion. The animal 
lives in a thick mud tube, in which are embedded immense numbers of sponge 
spicules. Owing to difficulty of penetration, many of the animals inside the tube 
were very poorly preserved. 
Mouth with prominent upper lip, with short tentacle-like processes at outer edge 
on either side, the number of these not constant. 
Median tentacle very long, as long as whole anterior region of body, flat, with 
edges, rolled so as to form a shallow longitudinal groove, much as in tentacle of 
Phyllochxtopterus. Two or three much smaller lateral tentacles on either side. 
Gills in a band of 8 finger-shaped processes, on dorsal surface; each gill tapering gently to blunt 
point at apex; smallest in center of band, largest on outer end. Bases of gills in contact with one 
another, though there is some indication of a double row arrangement. 
Fig. 72. — Uncinus 
of Terebellides 
tentacula, new 
species, x 280. 
Setse of thorax long, smooth, gently tapering from a broad base to a very delicate point. Two 
sizes of these setse appear, but this size difference is possibly due to age differences. 
Uncini of thorax in a single row. Teeth 5 in number, increasing in size, beginning at the apex, 
from 1-4, the fifth being smaller than the first (fig. 72). 
Abdominal somites much smaller than thoracic, with uncini like those of thorax. 
Collected at station 4126, 278-743 fathoms, on gray sand and foraminifera. Type no. 5220, 
U. S. National Museum. 
