SABELLIDES AND SERPULIDES 211 



mens are much paler. Number of segments about 340, of which 8 

 belong to the thoracic region. They are very short on the abdomen, 

 so that the tori are closely crowded. Branchial lobes forming well- 

 separated spires of about 2^ turns, measuring about 16 mm. in height, 

 without branchiae. 



Branchiae long and flexible, the longest from 33.5 to 36.5 mm. in 

 length in different specimens, numbering 125 to 135 in each lobe, and 

 usually arranged in a single series ; occasionally one occurs which has 

 an additional one in front of it ; one is also sometimes divided. 



Eyes of good size, varying in number on different sj^ecimens and 

 also in number and relative position on the same specimen. 



Collar increasing abruptly in height from the wide angular lateral 

 notches, slanting obliquely forward at a considerable angle, with 

 slightly undulating margin and ending in two prominent angular 

 processes on either side of the median ventral fissure. 



Dorsal furrow very deep on the first few segments, turns to the right 

 at the seventh segment, passes diagonally across the eighth segment to 

 the ventral region, then diagonally across the first abdominal segment, 

 turning downward into the ventral groove at the second segment. 



Length of largest specimen 12 inches, breadth at end of thorax 

 about 17 mm. ; length of thorax along setae about 13 mm., varying in 

 different specimens from 11 to 15 mm. Another perfect specimen is 

 9.75 inches long and about 15 mm. Avide. 



Tube solitary, more or less bent, of a tough brownish chitinous sub- 

 stance, the rough surface usually covered along the exposed portion 

 with sponges, ascidians, hydroids, seaweeds, etc. 



Yakutat, June 22, two small specimens ; Orca, Prince William 

 Sound, June 25, ten large specimens ; Virgin Bay, Prince William 

 Sound, June 26, two small specimens. 



Some of the specimens are abnormally developed. In the one fig- 

 ured, where an injury has been repaired, the symmetry in the arrange- 

 ment and form of the thoracic sctjE is interrupted, on one side between 

 the sixth and seventh segments and on the other between the seventh and 

 eighth. The additional one has no slender lanceolate superior setae, 

 but a somewhat elliptical fascicle of spatulate setae, like the inferior ones ; 

 no torus, but an elliptical fascicle of setae similar to those on the abdo- 

 men. Another, which also shows repairs of injuries, has 10 thoracic 

 segments and smaller branchial lobes forming spires of about i^ turns, 

 with but 70 to 80 shorter (about 27 mm.) branchiae arranged mostly 

 in a double series, sometimes branched, rarely more than once. The 

 avicular hooks also vary somewhat in form. 



