1906.] NATURAL SCIENCES OF PHILADELPHIA. 217 



ADDITIONAL NEW SPECIES OF POLYCH^TA FROM THE NORTH PACIFIC. 



BY J. PERCY MOORE. 



In the following pages are described a number of new species of 

 Polychaeta, belonging to several families, from the collections of the 

 Alaskan Salmon Commission of 1903. Three papers noticing other 

 novelties in these collections have already been published in these 

 Proceedings with the approval of the Commissioner of Fisheries, 

 through whose kindness the material was placed in my hands for study. 

 The full report on all of the species represented will appear in the 

 Bureau of Fisheries Bulletin. 



Notophyllum imbricatum sp. nov. Plate X, figs. 1-3. 



The two examples upon which this species is founded bear a re- 

 markable resemblance in proportions and general aspect to a Polynoe. 

 The body is depressed and the large, scale-like notopodial cirri are 

 imbricated and, except for a short space near the anterior end, com- 

 pletely conceal the back from above. 



The type and larger specimen is a trifle over 30 mm. long, and the 

 greatest width between tips of the parapodia a little anterior to the 

 middle of the body is 6.5 mm. The small individual is 12 mm. long 

 and 1.8 mm. wide, and the back is concealed by the elytra even more 

 completely than in the larger one. 



The prostomium is flattened and wedge-shaped, with the slightly 

 concave or straight base about two-thirds of the length, and the 

 angles rounded. A slight emargination of the anterior portion of the 

 sides is filled by an irregular low tubercle from which the frontal cirri 

 arise. A pair of large brown eyes occupy the greater part of the 

 posterior region of the prostomium laterad of the median tentacle 



(fig. !)• 



The frontal tentacles arise in lateral and ventral pairs, the latter 

 slightly in advance, from the slight emargination above mentioned. 

 They nearly equal the prostomium in length, are stout and somewhat 

 swollen above the base, and taper to fine tips. The median tentacle 

 arises between the eyes and nearly fills this space. It is one and one- 

 half times as long as the prostomium, stout and somewhat enlarged 



