242 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 



Body short and stout, little tapered to near the caudal end. 

 Fecal groove indistinct on thorax but well developed on venter of 

 abdomen. Ventral plates well developed throughout, generally 

 about four times as wide as long except on extreme caudal segments; 

 those on abdomen divided in halves by fecal groove. Pygidium a 

 small simple ring with large anus looking caudo-ventrad. 



Ventral setae on thorax wider than those figured for P. media and 

 more like those figured for P. rnaculata by Miss Bush. The beaked 

 setae on the other hand more closely resemble those of the former 

 although the cleft at the base of the mucron is less marked. 



This is \eTy probably the "small colorless species" recorded by 

 Miss Bush from Pacific Grove. 



Type only, a small somewhat contracted specimen 15 mm. long 

 and 1.5 mm. diameter. Thoracic segments 9 (8 setigerous), ab- 

 dominal segments 50. 



Station 4496, off Santa Cruz Lighthouse, 10 fathoms, fine gray 

 sand and rock. 



Pseudopotamilla splendida Moore. 

 V Two typical specimens from station 4341, off' South Coronado 

 Island, 188-323 fathoms, gray sand, and one each from stations 

 4420, off San Nicholas Island 32-33 fathoms, fine gray sand, and 

 4546, off Point Pinos Lighthouse, 849 fathoms, black sand. 



PseudopotamiUa brevibranchiata Moore. 



U 



Two fine specimens represent this species. The cephalic eyes 

 are conspicuous, very deep red spots confined to the more dorsal 

 radioles and distributed within a zone occupying the second fifth 

 of their length. The exact distribution on one specimen is as 

 follows, the radioles being numbered from the dorsalmost: Left 

 side, 1st— 0, 2nd— 3, 3rd— 3, 4th— 2, 5th— 2, 6th to 8th— 1 each; 

 right side, 1st— 0, 2nd— 3, 3rd— 3, 4th— 2, 5th— 3, 6th and 7th— 

 each 2, 8th and 9th — each 1. 



Stations 4421, off San Nicolas Island, 229-298 fathoms, gray 

 mud; 4496, off Santa Cruz Lighthouse, 10 fathoms, fine gray sand. 



Tubes of Pseudopotamilla were found at stations 4433 and 4519 

 also. 



Potamilla neglecta (Sars) ISIalmgren. 



\/ This circumboreal species is represented by four worms and a 

 large number of tubes. No eyes or other pigmentation occur on 

 any of the gills. The ventral collar lobes which are much elongated 



