No. 9.— Studies from the Newport Marine Zoilogical Laboratory. 
Communicated by ALEXANDER AGASSIZ. 
Dt Mid ig 
On the Development of Certain Worm Larve. By J. WauTER FEWKES. 
Prionospio tenuis VERE. (?). 
Plates I. and Ii. 
The youngest larva (PL I. Fig. 1, Pl. Il. Fig. 7) of this worm has a trans- 
parent head and a body which is 2-3 mm. long, tapering uniformly from ante- 
rior to posterior extremity. The head (PI.I. Fig. 1) has four eye-spots, or 
* The present paper, which is the first to appear under the above title, is one 
of a series from my Newport Laboratory, of which the following have already 
been published : — 
Vill. 
XII. 
The Development of Salpa. By Wm. K. Brooks. pp. 58. 34cuts. March, 
1876. Bull. Mus. Comp. Zool., Vol. III. No. 14, p. 291. 
. On the Young Stages of some Osseous Fishes. By A. Acasstz. I. De- 
velopment of the Tail. pp. 10. 2 plates. 1877. Proc. Amer. Acad., Vol. 
XII. p. 117. 
. The Development of Lepidosteus. By A. Acassiz. pp. 11. 5 plates. 
1878. Proc. Amer. Acad., Vol. XIV. p. 65. 
. On the Young Stages of some Osseous Fishes. By A. Acassiz. II. Devel- 
opment ofthe Flounders. pp. 24. 10 plates. 1878. Proc. Amer. Acad., 
Vol. XIV. p. 1. 
. On some Young Stages in the Development of Hippa, Porcellana, and Pin- 
nixa. By Watter Faxon. pp. 16. 65 plates. April, 1879. Bull. Mus. 
Comp. Zodél., Vol. V. No. 11, p. 254. 
. On the Development of Palemonetes vulgaris. By Watter Faxon. 
pp. 27. 4 plates. September, 1879. Bull. Mus. Comp. Zodl., Vol. V. No. 
15, p. 303. 
. Contributions to a Knowledge of the Tubular Jelly-Fishes. By J. Warter 
Fewkes. pp. 20. 3 plates. March and April, 1880. Bull. Mus. Comp. 
Zool., Vol. VI. No. 7, p. 127. 
On some Points in the Structure of the Embryonic Zoéa. By Watter 
Faxon. pp.7. 2 double plates. October, 1880. Bull. Mus. Comp. Zodl., 
Vol. VI. No. 10, p. 159. 
. Studies of the Jelly-Fishes of Narragansett Bay. By J. Warter Fewkes. 
p. 42. 10 plates (3 double). February, 1881. Bull. Mus. Comp. Zoidl., 
Vol. VIII. No. 8, p. 141. 
. On the Development of the Pluteus of Arbacia. By J. Watter Fewxes. 
pp. 10. 1 double plate. May,1881. Mem. Peabody Acad. Sci., I. 6. 
. On the Acalephe of the East Coast of New England. By J. Water 
Fewxes. pp.19. 1 double plate. April, 1882. Bull. Mus. Comp. Zodl., 
Vol. IX. No. 8, p. 291. 
On the Young Stages of some Osseous Fishes. III. By A. Acassiz. 
pp. 82. 20 plates. 1882. Proc. Amer. Acad., Vol: XVII. p. 271. 
ALEXANDER AGASSIZ. 
VOL. XI. — NO. 9. 
