298 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



There is considerable variation in the first appearance of branchiae. 

 In some from southern Florida they are present from the fourth seti- 

 gerous segment; and in some from the Galapagos Islands they are 

 present first on the sixth, eighth or ninth segments and already long and 

 filiform. On others they are absent from the first 1 1 segments, small on 

 20 or more segments, and rapidly increase in size only in abdominal 

 segments. The transition from thorax to abdomen is also variable but 

 generally occurs between segments 14 to 30, with an additional two 

 segments transitional. In thoracic neuropodia the postsetal lobe is broad- 

 ly foliaceous and prolonged at its superior edge (figs. 1, 2). Branchiae 

 are laterally fimbriated. 



Thoracic neurosetae include many pointed setae (fig. 4) in two or 

 more anterior series, followed by uncini and subuluncini. The uncini 

 (figs. 6, 7), numbering 5 to 12 in a row, are slenderer than or as heavy 

 as subuluncini and located in more inferior positions. The lowermost 

 are distally hooded (fig. 6) ; the uppermost are larger and without hood 

 (fig. 7). Subuluncini (fig. 5) are located in the uppermost part of the 

 fascicle behind the pointed setae. They resemble uncini in which the 

 distal end is prolonged and spinous. Thoracic notopodia have slender 

 pointed setae and slender embedded acicula, and in more posterior seg- 

 ments there may be a few furcate setae (fig. 8). 



Abdominal notopodia have long pointed setae, one or two furcate 

 setae (fig. 8), and three to five thick, yellow acicula more or less com- 

 pletely embedded or with their distal ends free (fig. 3). The furcate 

 setae have tines of unequal length and a shaft spinous along one side 

 (fig. 8). 



Eisig (1914, pp. 450-488) referred a long list of names to this 

 species, including Anthostoma hexaphyllum Schmarda, which is con- 

 sidered distinct by Monro (1930, p. 145) and Augener (1918, p. 421) 

 (see also Key to Species above). Aricia setosa Verrill is a distinct species; 

 Naineris robusta and N. longa, both by Moore from California, are 

 here referred to Naineris dendritica (see below). 



Distribution. — Naineris laevigata is known from cosmopolitan areas 

 in warm seas in littoral zones. In the eastern Pacific Ocean it is known 

 from the Galapagos Islands, Ecuador (Monro, 1933, p. 1045) and 

 Peru (newly recorded herein). It is replaced by the nearly related 

 Naineris dendritica in the northeastern Pacific Ocean (see below). 



