276 PROCEEDINGS OF THE ACADEMY OF [April, 



the crest teeth less prominent but more numerous and subdivided. 

 The tubes resemble those of T. cincinnatus ; sometimes they are covered 

 with shell sand. 



Polycirrus sp. ? (Plate IX, fig. 54). 



A much macerated Polycirrus, dredged at Delmonte wharf, Monterey 

 Bay, on July 12, 1904, has uncini very closely resembling those of P. 

 aurantiacus (Grube) Malmgren, but is too imperfect for description. 



Polycirrus califomicus sp. nov. (Plate IX, figs. 52, 53). 



The type is 28 mm. long, about 1.5 mm. in maximum diameter and 

 has 65 segments, 28 of which are setigerous. 



Prostomium large, projecting far forward as a long, narrow, highly 

 arched lobe shaped much like the inverted bowl of a spoon, about 

 twice as long as wide and equaling the first four segments. No eyes. 

 Tentacles very numerous, forming a densely tangled mass which 

 conceals much of the anterior end of the body, of two kinds, one very 

 slender and delicate, slightly enlarged distally and arising from a pair 

 of lateral areas, the other stouter with thin marginal expansions and 

 arising from a transverse band near the anterior border of the 

 tentaculiferous area. 



Peristomium a short, simple ring bounding the mouth; other seg- 

 ments varying in size with the degree of distention of the ccelom, the 

 anterior ones faintly biannulate and the intersegmental furrows usually 

 rather obscure; dorsum smooth and strongly arched, a longitudinal 

 furrow immediately above the setigerous tubercles. Venter with a 

 deep neural groove bounded by prominent lateral muscular ridges 

 supporting the parapodia. 



First ventral plate entire, equilaterally triangular, the apex forward, 

 extending the entire length of the peristomium and somite II, followed 

 by eight short, oblong, ventral plates, each divided into equal quadrate 

 halves by the deep neural groove, the first five reaching the full length 

 of somites III to VII, the remaining three on segments VII to X being 

 reduced in size. 



The last ten or twelve segments taper very rapidly to a minute 

 simple pygidium. Coelom packed full of small eggs. 



Setigerous tubercles begin on II and continue to XXIX (inclusive). 

 They are small, project dorsad and laterad and bear small fan-shaped 

 fascicles of delicate colorless setse arranged in pairs of a small simply 

 capillary setse and a longer limbate one. After about XX the fas- 

 cicles become much smaller and inconspicuous. Tori begin on XIV, 

 at least no trace of uncini can be detected anterior to this segment. 



