300 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



Variations in uncini and transitional setae are noted when comparing 

 individuals from Alaska and Washington and south to southern Cali- 

 fornia. Those from northern localities have pale yellow setae; the more 

 southern ones have darker setae and the individuals are proportionately 

 smaller. 



Abdominal segments have parapodia (pi. 36, fig. 3) resembling those 

 of N. laevigata (compare pi. 35, fig. 3). Notopodia have long pointed 

 setae and a few furcate setae (pi. 37, figs. 1, 2) in which the tines are 

 unequally long and the shaft is spinous. Neuropodia have shorter pointed 

 setae and a transverse series of yellow acicula (pi. 37, fig. 3) extending 

 a short distance from the parapodium. 



Naineris dendritica is distinguishable from N. laevigata (see above) 

 by characters which may be only subspecific or varietal. They concern 

 mainly the details of postsetal lobes in thoracic neuropodia and micro- 

 scopic details of the setae and uncini. Their separation is here maintained 

 because of the differences in geographic range (see distribution below). 



Distribution. — Naineris dendritica is limited to littoral zones of the 

 northeastern Pacific Ocean from Alaska south to southern California. 

 It is common especially in sandy muds supporting abundant plant 

 growth. 



Naineris jacutica Annenkova, 1931 



Nainereis jacutica Annenkova, 1931, pp. 204-205, figs. 1-4. 



This is said to measure about 85 mm long and it has a prostomial 

 lobe that is semicircular. Branchiae are present from segment 8 or 9 

 and continue to the end of the body; the first are small but from seg- 

 ment 16 to 18 they are longer than their accompanying postsetal lobes. 

 Transition from thorax to abdomen occurs at segments 20/21. In its de- 

 tails it agrees with TV. laevigata (see above) except that furcate setae 

 are said to be altogether absent. 



Distribution. — Naineris jacutica is recorded from the Sea of Ok- 

 hotsk and Bering Sea. 



Naineris mutilata (Treadwell), 1931 



Nainereis mutilata Treadwell, 1931, pp. 5-6, figs. 13-18. 

 Naineris mutilata Hartman, 1956. 



The thorax consists of 29 setigerous segments, with the last two 

 transitional. Branchiae are present from the third setigerous segment; 

 the first few are small and they increase in size gradually in the thorax; 



