320 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



of curved yellow acicular hooks that number 4 to 7 in a series; the 

 largest are uppermost and the others gradually diminish in size. These 

 hooks are accompanied by about twice as many long, slender capillary 

 setae in which the longest are uppermost, the shortest lowermost. The 

 approximate proportionate thickness of hooks and setae is shown in 

 fig. 7. 



Branchiae are first present from the fourth setigerous segment and 

 number 15 to 30 pairs; they are large and erect over the dorsum. Each 

 is thick or somewhat compressed and tapers to a slender distal filament. 

 The first three segments have full spreading fascicles of long pointed 

 setae directed outward and back in flowing tufts. 



The notopodial postsetal lobe in postbranchial segments is slender 

 and cirriform; it increases in length posteriorly so that it is as long as 

 the shortest setae ; on the last few segments it resembles the long pygidial 

 processes. The anal ring is a thick flange with a larger midventral cirri- 

 form process and a pair of slightly smaller though similar lateral ones. 



Two specimens from the lower end of the Gulf of California, Mex- 

 ico, taken from a soft shallow bottom, differ somewhat from those from 

 San Pedro Basin, California. The body is conspicuously marked with 

 brown segmental stripes (preserved) most conspicuous in the immediate 

 postbranchial region and less intense in anterior segments ; similar brown 

 pigment is irregularly present on the prostomium and the rest of the 

 body. The prostomium is depressed conical and has no eyes. Branchiae 

 are present from the fourth segment and number only 14 pairs. Posterior 

 abdominal neuropodia have transverse series of acicular setae that are 

 sharply bent in their distal end or slightly sickle-shaped ; the lowermost 

 are shortest and a little thicker than the longest uppermost in a series. 

 The posterior or pygidial region is missing. They were associated with 

 other annelids unlike those in San Pedro Basin and may thus represent 

 a different species. 



Individuals identified as near Aricidea suecica Eliason, from Cali- 

 fornia, differ from those in European collections in having branchiae 

 present on a larger number of segments ; the prostomium has no eyes ; 

 the proportions of posterior neuropodial hooks are somewhat different. 

 Whether these differences are more than variations is considered doubt- 

 ful. 



Distribution. — Aricidea near suecica has been found to be most 

 abundant in San Pedro areas, California, in soft shallow depths (Hart- 

 man, 1955, p. 170). It is doubtfully recorded from the southern end of 

 the Gulf of California, Mexico. 



