NO. 4 HARTMAN: POLYCHAETOUS ANNELIDS 415 



filaments ; they arise from the posterior end of the notopodial torus. How- 

 ever, abdominal lateral organs were described as distinct only posteriorly 

 where the tori become widely separated; thoracic lateral organs and 

 genital pores were not observed. Except for these differences there is 

 remarkable agreement. Since the ecological and geographical distribu- 

 tions are the same, I suggest that these individuals are actually conspecific 

 with those described as N. magnus but that they are probably not the 

 same as A^. giganteus Moore from deep water ofif Alaska. 'N. giganteus 

 Berkeley (1941, p. 48) from Anaheim Slough, California, may also 

 belong here. 



Notomastus giganteus Fauvel (1932, p. 194) from off Ceylon and 

 Orissa is perhaps some other species, since only the first 9 (instead of 20 to 

 24) pairs of genital pores are conspicuous and the abdominal notopodia 

 are obsolete to vestigial ; also the branchiae consist of a transverse row of 

 small filiform papillae instead of a dual branched structure as in 

 N. magnus (pi. 51, fig. 6). 



Holotype. — ^AHF no. 120; paratypes in the Allan Hancock Founda- 

 tion. 



Type locality. — Tomales Bay, California; intertidal. 



Distribution. — This species occupies an extensive geographic area. In 

 intertidal or littoral zones, from northern California south at least to 

 San Diego, California. It occurs in sandy mud flats that have daily 

 exchange of tidal currents and especially in zones that are covered over 

 by narrow-leaved eelgrass (Phyllospadix). 



Notomastus lobatus, new species 

 Plate 51, Figs. 1-5 



Collections.— n^lAO (1); 1069-40 (about 60 anterior ends). 



The longest and largest individual (station 1107-40) consists of 

 thorax and 47 abdominal segments (posteriorly incomplete) and measures 

 about 60 mm long and 5.5 mm wide in the thorax. Segments are 

 strongly biannulate in the thorax and the epithelium is finely areolated in 

 a longitudinal direction. The biannulation of abdominal segments is 

 somewhat obscured by 3 to 5 additional shallow grooves between suc- 

 cessive parapodial ridges. 



The proboscis (not everted in any individual) is papillated on its 

 proximal part and perhaps over much of its surface (observed by dis- 

 section). The prostomium is a plain, triangular, slightly depressed lobe, 

 without eyespots but with a pair of nuchal slits at its posterior margin. 



