NO. 1 HARTMAN : POLYCHAETOUS ANNELIDS 87 



Distribution. — N. conchylega has remained unreported from the 

 temperate and tropical eastern Pacific, but has been noted from many, 

 parts of the eastern coast of North America. These records extend its 

 range from southern California, south to Port Utria, Colombia, and into 

 the West Indian region, with a bathymetric range of 5 to 103 fms. 



Nothria iridescens (Johnson) 

 Plate 5, Figs. 99-104 



Northia iridescens Johnson, 1901, p. 408, pi. 8, figs. 86, 87. 

 Moore, 1908, pp. 345-346; 1911, p. 255. 



Collections.— ^16-3% (2); 889-38 (2); 893-38 (4); 900-39 (3); 

 908-39 (4); 987-39 (2); 1002-39 (1); 1005-39 (1); 1018-39 (2); 

 1022-39 (1) ; 1122-40 (1) ; 1126-40 (2) ; 1132-40 (1) ; 1133-40 (about 

 30); 1134-40 (1); 1135-40 (1); 1137-40 (2); 1142-40 (3); 1146-40 

 (1); 1149-40 (1); 1157-40 (1); 1159-40 (1); 1163-40 (about 15); 

 1182-40 (1); 1191-40 (1); 1205-40 (4); 1226-41 (3); 1232-41 (1); 

 1235-41 (1); 1236-41 (1); 1241-41 (3); 1245-41 (2); 1251-41 (4); 

 1348-41 (1). 



These numerous specimens are usually marked with dark interseg- 

 mental grooves separating the paler segmental spaces. The ceratophores 

 are long, clearly annulate, provided with long, tapering styles. An outer 

 ceratophore has about 15 shorter articles and a longer distal one, its 

 style is about % as long. An inner paired tentacle has a ceratophore with 

 about 18 shorter articles and a longer one; its style extends back to about 

 the eleventh setiger. The median tentacle has a ceratophore with about 

 10 shorter articles and a longer distal one; its style extends back to about 

 the third setiger. The prostomium has a pair of small, dark eyespots be- 

 tween the bases of the outer and inner paired tentacles. 



Branchiae are present from the first setiger, as a single, long filament 

 and continued throughout. Ventral cirri are cirriform through 6 or 7 

 setigers, padlike thereafter. Subacicular hooks (pi. 5, fig. 99) are first 

 present from the thirteenth to fifteenth; they occur 2 in a parapodium 

 thereafter. 



Anterior parapodia have tridentate, pseudocomposite, hooded hooks 

 that resemble one another; the distal tooth is usually the longest (pi. 5, 

 figs. 100, 102), rarely it may be shorter (pi. 5, fig. 101), but there are 

 no simple, acicular hooks such as are found in N. elegans (below). A 

 third parapodium has 6 tridentate hooks, the form nearly constant, but 

 some are slenderer, with the articulation a longer or shorter distance 

 from the tip; there are also 3 or 4 slender, simple, pointed setae and 3 



