JOHNSON: POLYCHAETA OF PUGET SOUND REGION. 415 
Length of head and anterior region, 7 mm.; length of first 12 
somites of abdomen, 8 mm.; greatest transverse diameter, 1.5 mm.; 
length of tentacular cirri, about 14 mm. 
Two imperfect specimens, consisting of only a few anterior 
somites, represent this interesting species. It was collected 1^ 
Miss Robertson at West Seattle, June 23, 1899. 
Mag el ona pap ill i cornis, originally described by Fritz Muller (’58) 
from the Island of Santa Catharina off the coast of Brazil, has 
since been found on both sides of the North Atlantic (vide 
Andrews, ’91). Its anatomy, both external and internal, has been 
carefully studied by MTntosh (’78) and its remarkable blood has 
been investigated by Benham (’96). Hitherto it has remained a 
unique and isolated form, most closely related to the Spionidae but, 
as M’Intosh pointed out, having affinities also with the Chaetop- 
teridae. The present species differs from M. papillicornis (1) in 
its much greater size, (2) in the greater length of its tentacular 
cirri and longer papillate areas of same, (3) in the comparative 
shortness of the prostomium, and (4) in the smoothness of the 
proboscis. 
Capitellidae. 
31. Capitella dizonata sp. nov. PI. 11, figs. 119-121. 
Thorax thickest in region of 5th and 6tli somites; smallest at 
8th and 9th (Fig. 119), most of the thoracic somites two-ringed ; 
abdominal somites three- to twelve-ringed; intersegmental con¬ 
strictions pronounced, especially in thorax. 
Prostomium short, conical, at base slightly more than one half 
the diameter of the peristomium; nuchal organs not discovered. 
Peristomium setigerous; somites of thorax over three times as 
broad as long in the contracted state; the 4tli and 5th each with 
a dark brown band passing around it in front of the fascicles. 
Female genital pore between the 7th and 8th somites (9^ Fig. 
119). 
Abdominal somites notably longer than the thoracic, beginning at 
the 10th, which differs but slightly from the 8th and 9th of the 
thorax; increase caudad in length and number of rings. I ncini- 
gerous tori placed near the posterior boundary of each segment; 
the ventral the first to appear, and larger than the dorsal through¬ 
out anterior region of abdomen. 
