Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
10. 
ie: 
33. 
34. 
an 
36. 
37. 
38. 
39. 
POLYCH ET LARVA. 651 
Puate ITI. 
Nephthys.—Metatrochophore, ventral aspect. » 75. 
(From a mounted specimen only.) 
Nephthys.—Setae. (A) Frilled seta; (B) Smooth 
seta. 
Spiomd B.—Nectosoma, anterior end, dorsal aspect. 
<x 75. (From a mounted specimen only). S. per., 
permanent setae; S. prov., provisional setae. 
Posterior end of the same larva, ventral aspect. > 75. 
Spionid C.—Metatrochophore. (From a_ preserved 
specimen except for the eyes.) X 79. 
Spiond D.—Metatrochophore, fully contracted. 
x 75. (From a mounted specimen only). 
Spiond D. Anterior end cf more advanced and well 
expanded Metatrochophore. x 75. Only the 
bases of the setae shown. /Pr., snout-like anterior 
prolongation of the prostomium. 
Spio.—Metatrochophore. x 75. (From a mounted 
specimen only.) 
Magelona.—Nectosoma which has shed the provisional 
setae from all segments of the anterior body- 
region except the first; the larval region of the 
tentacle of the left side has also been shed; x 75. 
S. per. cap., permanent capillary setae of the 
anterior body-region; 8S. per. cr., crotchets 
(permanent setae) of the middle and posterior 
body-regions; SS. prov., provisional setae of the 
first segment and of the middle body-region ; 
T. larv., larval portion of the night tentacle ; 
T. per., permanent portion of the tentacles. 
Figs. A. and B. Diagrams of akrotroch of Phyllodocid C.— 
(A) Profile; (B) Surface view. /., lateral extensions ; 
m., median piece; m. J. c., median long cilia; 
p. hk., paired “hook” of long cilia. 
Fig. C. Trochophore of Nerine cirratulus. (After Leschke, 
modified from Cunningham and Ramage). 
