NOTE ON THE EARLY LARV.E OF NEPHTHYS AND GLYCEKA. 167 



teen days dd. The upper hemisphere is larger and bhmter than the 

 lower. There is a patch of cilia extending from the lower lip of the 

 mouth towards the anus, which is terminal. The apical cilia are 

 usually motionless. Light green pigment has appeared in an in- 

 complete band round the upper hemisphere, and a pair of patclies on 

 either side of the anus. These latter are characteristic of the larva of 

 Ncplithys (3). The large stomach, which fills the greater part of the 

 upper hemisphere, has a dark green pigment in its basal walls, the 

 remainder of the gut being yellow in colour. The intestine is sac-like. 



The larva described above differs very much from that figured 

 by Claparede and Mecznikow (2). It resembles in some points that of 

 Fewkes (3), but is of a different shape. Hacker (5) and Gravely (4) 

 described the Metatrochophore and later stages only. 



Swimming blastulse of Glycera convoluta appear some ten hours after 

 fertilization, and the trochal ring is formed in twenty-four hours. An 

 early larva is shown in Fig. 4. It is spherical and granular with a 



Fig. 4.— Larva of Glycera. 26 hours. 

 op. c. — Apical cilia. 



ciliated troclial ring and an apical tuft of long cilia. Fig. 5 sliows 



Fig. .">. — Larva of Glycera. 58 hours. 

 Left side view. m. — Moutli. 



