Annelids of Alaska—H artman 
23 
Typosyllis collaris new species 
Fig. 6 a-c. 
Collection. Station D 8-41 (4). 
Several small individuals are colorless except 
for the four red eyes; the largest one measures 
12 mm. long for 45 segments but is posteriorly 
incomplete. The body is short and plump. The 
prostomium is broader than long; it has a long 
median, and two shorter lateral, antennae and 
the four eyes are in trapezoidal arrangement 
(Fig. 6 a); the posterior portion is somewhat 
overlain by a nuchal lobe (hence the specific 
name) which extends forward to the posterior 
margin of the posterior eyes. The prostomial 
antennae are articulate, most distinctly so in 
their distal halves and decreasingly so to near 
their bases; the median one is more than twice 
as long as the paired ones (Fig. 6 a). The palpi 
are free from one another except at their bases; 
they are broadly subrectangular and about as 
wide as long. 
The proboscis terminates distally in 10 soft, 
widely spaced papillae; on its dorsal side at the 
anterior end there is a conspicuous semitranslu- 
cent greenish tooth, equitriangular in shape. 
The proportions of prostomial antennae, tenta¬ 
cular cirri, and anterior dorsal cirri are shown 
in Figure 6 a. 
The parapodia are short and plump but taper 
slightly distally. The anterior ones resemble the 
posterior, except that setae tend to be more 
numerous in front. Dorsal cirri are articled in 
their distal halves but are more or less smooth 
at the base. In anterior parapodia the postsetal 
lobe is slightly prolonged but the setal lobe is 
blunt. In median and postmedian parapodia 
(Fig. 6 b) the presetal lobe is somewhat drawn 
out and shorter than the postsetal one. 
Setae are entirely composite and resemble 
one another throughout. The superior and in¬ 
ferior ones in any fascicle, as also those in 
anterior and posterior segments, are similar to 
one another, but the appendage of the first is 
slightly longer than that in the last. They num¬ 
ber 25 to 30 in anterior segments and decrease 
to 15 to 18 in posterior segments. The shaft is 
distally spinous; the appendage is short, boldly 
bidentate at its free end and there are a few 
long spines along the cutting edge (Fig. 6 c). 
Acicula are pale yellow, slightly knobbed dis¬ 
tally, and number usually two in a parapodium. 
Fig. 6. Typosyllis collaris new species: a, anterior end in dorsal view, enlarged; b, postmedian parapodium 
dn anterior view, only some of the 18 setae shown, X 89; c, seta from a median parapodium, X 956. 
