LEWIS: CLYMENE PRODUCTA. 
113 
show much variation in size. In both forms the setae taper very 
gradually and uniformly to a sharp point. In the simpler form 
(PI. 2 , Fig. 1G) the seta is entirely smooth; in the other (PI. 2 , 
Fig. 17) it is provided with bipinnately arranged spinous hairs, 
which give it a plumose appearance when seen under the microscope. 
The ventral setae are uncini (PI. 2 , Figs. 13,14, 10, 11) and show 
a marked difference of form in the case of the thoracic and the 
remaining segments. In the thorax there are only two (PI. 2 , 
Figs. 13, 14) in each parapodium, and one of these is not evident 
upon superficial examination, because it is not protruded beyond the 
surface of the segment. They are rather short and stout, and the 
free end terminates in a single slightly curved, rather blunt process. 
The less evident one (PI. 2 , Fig. 13) scarcely projects beyond the 
surface of the body. It differs from the other especially in the form 
of the inner end, which is very blunt. 
The abdomen has a large number of uncini in each ventral ramus. 
Beginning with 16-18 in the first abdominal segment, the number 
rapidly increases, so that in the fifth abdominal segment there are 
37-40 in each ventral ramus. These uncini (PI. 2 , Figs. 10, 12) end 
sometimes in four, sometimes in five hooks; the foremost of these 
hooks is the largest, the others are successively smaller. Each 
uncinus bears a tuft of bristles at the base of the largest hook. The 
uncini from the abdominal segments (PI. 2 , Fig. 10) are curved 
less than those (PI. 2 , Figs. 11, 18) from the first segments of the 
tail region ; otherwise they resemble them closely. 
As a whole, the worm is of a pinkish flesh color. There is a con¬ 
spicuous bright red band around the posterior portion of each of 
the five segments of the abdomen. The most anterior of these 
bands is very narrow, but they increase successively in width until 
the fourth abdominal segment is reached, in which the red band 
occupies about two thirds of the segment (PI. 1, Fig. 8). In 
preserved specimens the anterior portions of these banded segments 
are of a dull whitish color. The posterior portion of the fifth 
abdominal segment, the ninth segment of the worm, has a red band 
of a less pronounced character than the four preceding it. 
There are three pairs of nephridial openings, one pair each in 
segments eight, nine, and ten. They are ventral and a little 
posterior to the row of uncini (PI. 1, Fig 8). Corresponding with 
these openings there are, as I find by dissection, three pairs of 
nephridia. 
