174 Proceedings of the Biological Society of Washington. 



5. Lejpidonotus coeloris Moore. 

 Proc. acad. sci. Phil., 1903, p. 412, pi. 23, f. 12. 



SYLLID^. 



6. Syllis alternata Moore. 



Proc. acad. sci. Phil., 1908, p. 323. 

 One specimen. 



NEREIDS. 



7. Nereis procera Ehlers. 

 Die Borstenwurmer, 1868, p. 557, pi. 23, f. 2. 



8. Nereis mediator Chamberlin. 



Pomona coll. journ. ent. and zool., 1919, 11. 



A species previously known from Laguna Beach and San Diego, Cal. 



9. Nereis mendocinana Chamberlin. 



Previously known from Mendocino, Cal. 



10. Nereis (Neanthes) monterea, sp. nov. 



Apparently the only species thus far known from the Pacific Coast in 

 which all areas of the proboscis are armed and of the Neanthes type. In 

 area I a single conical tooth which is very much stouter than those of other 

 areas of the maxillary ring. On each area II in the type are six denticles 

 in three transverse rows, the arrangement, beginning with the distal series, 

 being 1, 2, 3. On III are numerous denticles in typically four transverse 

 series; the denticles of the two middle series obviously stouter than those 

 of the others; example of arrangement, 3, 4, 9, 9. Denticles of IV also 

 numerous, in a patch elongate in a longitudinal direction, typically in 

 five series, with five denticles in each. A single stout tooth like that of I in 

 area V. In VI a still larger conical tooth which is usually compressed in the 

 distoproximal direction, plate-like. Denticles of VII and VIII forming 

 a continuous band across sides and ventral region of ring, the band a single 

 series at sides but composed of two or three denticles below, the denticles 

 much larger than those of the maxillary ring excepting that of I. Pros- 

 tomium in length about equalling the first two segments together, a little 

 longer than width across base; posterior oculiferous region subquadrate, 

 broader than the longer anterior region, which is more depressed, flatter, 

 and is separated from the basal by a transverse depression, its anterior 

 end convex. Tentacles separated by about their radius, conical, short, 

 less than half the length of prostomium and often not more than a third. 

 Anterior eyes a little longer than the posterior, from which well separated, 

 and a little farther apart. Palpi very stout, outline of the two joints 

 smoothly continuous, the terminal one short, strongly rounded, hemis- 

 pherical. Peristomium about once and a half the length of II, much longer 

 below, on sides and ventrally crossed by numerous oblique furrows. Dorsal 



