1903.] natural sciences of philadelphia. 801 



Explanation of Plate LV. 



Figs. 1 to 12. — Drieschia pellucida. 



Fig. 1. — Dorsal view of entire worm with the elytra removed. X 11. 



Figs. 2 to 5. — -Parapodia of somites X, IV, IX and XIV respectively, viewed from 



the posterior face, XIV only with the setee. X 24. 

 Fig. 6. — Front view of the proboscis, showing jaws and papillae. X 56. 

 Fig. 7.— One of the shortest of the slender setaj from the ventral margin of 



somite XIV. X 250. a, a small portion of the same. X 440. 

 Fig. 8. — Face view of a seta from the middle of the first parapodium (II). 



X 360. 

 Figs. 9 to 11. — The tips of three stout setse from .somite X, 9 having the 



pennant-like tip, 10 the most ventral and 11 the most dorsal of the 



group. X 360. 

 Fig. 12.— Face view of a stout seta with tip intact from somite XIV. X 360. 

 Fig. 13. ^Outline of a typical parapodium fV) of a medium-sized Toynoptrrif 



from Crab Ledge, showing the rosette-organs, dr and vr, the fin gland, gl, 



and the ovaries, o, the latter being represented diagrammatically. X 24. 



51 



