178 



PROCEEDINGS OF THE ACADEMY OF 



[Jan., 



coarse serrations on edge, seen under a 7 objective, Uncini very 

 narrow, the teeth too fine to determine. Abdominal setse and uncini 

 not seen. 



- Steamer Albatross, May 8, 1900, at Station 

 3,707, off the coast of Japan, in 63-75 

 fathoms. Five specimens on fragments of 

 mollusks and pebbles. 



Spirorbis dorsatus Bush sp. nov. 



Tube small, regularly coiled, dextral, dif- 

 fering from the preceding (S. bellulus) in 

 having but one very prominent keel on the 

 middle of the whorls, rendering the tube 

 three-sided. A small nematode worm and 

 sand filled the tube, but no animal was 

 found. 



Three specimens were found with the pre- 

 ceding, at Station 3,707, in 63-75 fathoms. 

 As no animals were found, it is impossible to determine whether or 

 not these tubes may not be the young of S. foraminosus. 



Fig. h. S. bellulus, seta 

 from collar fascicle. 



Explanation of Plates XI and XIT. 



Plate XI, Fig. 1. — Sabella japonica. Slender lanceolate seta from ventral part 

 of the fascicle of V, X 480. 



Fig. 2. — Sabella japonica. Small imcinus from the dorsal part of the torus 

 of V, X 480. 



Figs. 3-6. — Potamilla acuminata. 



Fig. 3. — Slender seta from dorsal part of VI, X 335. 



Fig. 4. — Face view of a slender seta from XL, X 335. 



Fig. 5. — Two views of a spatulate and mucronate seta from ventral part 

 of VI, X 335. 



Fig. 6. — A pick-shaped uncinus from VI, showing a slender tip of about 

 the average length, X 600. 



Figs. 7-13. — Hypsicomus lyra. 



Fig. 7. — Limbate seta from the ventral series of the collar fascicle, X 480. 



Fig. 8. — Hooded seta from the dorsal series of the same, X 480. 



Fig. 9. — Limbate seta from the dorsal part of V, X 335. 



Fig. 10. — Plain paddle-shaped seta from the ventral part of V, X 335. 



Fig. 11. — Mucronate paddle-shaped seta from the same, X 335. 



Fig. 12. — Bilimbate pointed seta from a posterior abdominal somite, X 335. 



Fig. 13. — Pick-shaped uncinus from VI, X 480. 



Figs. 14, 15, 16. — Euchone alicaudata. 



Fig. 14. — Outline of slender seta from the dorsal part of V, X 480. 



Fig. 15. — One of the more symmetrical broadly bilimbate setse from the 

 ventral part of V, X 480. 



Fig. 16.— A crochet from VI, X 480. 



Fig. 17-18. — Protula geniculata. Abdominal and thoracic uncini respec- 

 tively, X 800. 



