1923] NATURAL SCIENCES OF PHILADELPHIA 199 



Anterior parapodia prominent, laterally eom])ressed, truncate 

 cones, the first smaller than the others, projecting dorso-laterad 

 from a level nearer to the venter than the dorsum. The first 

 seven (II-VIII) bear minute rounded tubercle-like tori, lacking 

 uncini, on the ventral face close to the base. Beginning with the 

 eighth (IX) the setigerous tubercles become relatively smaller 

 and the tori much larger and flattened with ear-shaped ends. 

 Farther back toward the end of the setigerous series the parapodia 

 become more ventral in position, smaller and the setigerous tubercle 

 a mere projection from the dorso-lateral angle of the flattened 

 torus. In the abdominal region following the disappearance of 

 the setigerous tubercles the parapodia have much the form of the 

 prolegs of a sphingid caterpillar. The number both of setigerous 

 and of uncinigerous segments is variable, the former running from 

 26 to 40, beginning always on II and the latter beginning on IX 

 on three specimens and continuing to the caudal end. On a large 

 specimen no uncini can be detected on the first eleven setigerous 

 segments and on another of average size, on the first nine. 



Setae form prominent flattened crescentic tufts and are colorless, 

 capillary and alimbate. Uncini form curved series along the free 

 border of the tori, apparently always arranged in a single series. 

 They are small, colorless and moderately numerous, exceeding 

 100 on the middle setigerous segments, and are distinguished from 

 those of most species of the genus by the relative prominence of 

 the beak; posterior ligament process also prominent and the liga- 

 ment long and slender. 



The tj^pe is 56 mm. long exclusive of the tentacles and 2.7 mm. 

 in maximum diameter. Segments 74, of which 40 are setigerous, 

 beginning with II; uncini begin on IX. 



Stations 4430, off Santa Cruz Island, 197-281 fathoms, black 

 sand, pebbles and rocks; 4463, off Point Pinos Lighthouse, 48-111 

 fathoms, rocky, (type); 4476, same locality, 25-39 fathoms, soft 

 green mud (cotypes) ; 4496, off Santa Cruz Lighthouse, 10 fathoms, 

 fine gray sand and rocks (fragment of a large specimen, 3.2 in. in 

 diameter). 



Terebellides stroemi Sars. 



This species is widely distributed on muddy bottoms and was 

 found especially abundant at Stations 4452, 4457, 4485, 4517 and 

 4522. The species is extremely variable and almost every colony 

 exhibits some slight though definite peculiarities. They may 

 aptly be compared to de Vries' elementarj'" species among plants. 

 These differences find expression chiefly in the form of the crochets 

 and the structure and proportions of the gills. 



