296 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



Genus Naineris Blainville, 1828 

 Type N. quadricuspida (Fabricius) 1780 



This is spelled also Nainereis Grube, 1850, Naidonereis Malmgren, 

 1867, and Naidoneris Webster and Benedict, 1887. It includes Nats 

 Fabricius, 1780, Anthostoma Schmarda, 1861, Lacydes Kinberg, 1866, 

 and questionably Theodisca Miiller, 1858. 



The prostomium is rounded in front. Branchiae are present from the 

 second, or not before about the twenty-third setigerous segment. The 

 thorax consists of 12 to 30 or more segments. Thoracic neuropodial 

 setae may include uncini which are hooded or not, subuluncini, and 

 pointed setae, or all setae may be pointed. Abdominal notopodia have 

 pointed setae sometimes accompanied by furcate setae. Subpodial lobes 

 and interramal cirri are absent. In all segments the branchial bases are 

 widely separated middorsally. 



Key to Species of Naineris 



1. All thoracic setae slender and distally pointed . N. setosa 



1. Some thoracic neuropodial setae uncinate or subuncinate . . 2 



2. Thoracic neuropodial setae largely slender and pointed except 

 for a small ventralmost fascicle of acicular uncini ; branchiae 

 present from third setigerous segment . . N. mutilata 



2. Thoracic neuropodial setae otherwise; branchiae first present 



on a more posterior segment 3 



3. Thoracic neuropodial postsetal lobe double (pi. 38, fig. 6) 

 N. uncinata 



3. Thoracic neuropodial postsetal lobe simple (pi. 35, fig. 1) 4 



4. Branchiae reduced in size and not present before about seg- 

 ment 20 to 23 and diminishing in size in posterior abdominal 

 segments, becoming inconspicuous . . N. nannobranchia 



4. Branchiae larger and not so reduced in abdominal segments 5 



5. Thoracic neuropodia provided with uncini (pi. 39, fig. 1) 



but no subuluncini 6 



5. Thoracic neuropodia with uncini and subuluncini (pi. 37, 



fig. 5) . . 9 



6. Thoracic uncini smooth N. retusiceps 



6. Thoracic uncini ridged, spinous or ornamented along their 



free length 7 



