430 MORGAN. [Vol. V. 



shown in the figure, where they were separated somewhat, so that 

 the course of the bands might be more clearly seen. The 

 radial symmetry is also somewhat distorted. 



Fig. 1 1 shows a part of a side view of the larva, spread out flat 

 on a slide, so that the circumoral area or furrow is seen between 

 the bands. Only by this means can the bands be traced with 

 certainty. The figure may be oriented by referring it to Fig. 6. 

 The one is of the right side, and the other the left. The letters 

 o and/ between the figures indicate the same bands. The band 

 o comes from above the mouth, runs along the side until it 

 reaches the point above q, and then turns upwards towards the 

 apical plate, and then the tentacular arrangement commences. 

 The band p comes from below the mouth and runs a parallel 

 course to o, and forms what I have spoken of as the lower limb 

 of the longitudinal band. At the point q this band makes a 

 slight upward course, then turns downwards, and then upwards 

 once more to o. The reference letters op and ac, in Figs. 1 1 

 and 10, show the relationships of the bands. The anterior lateral 

 fold is shown by ac in Figs. 10, 1 1, and 6. 



Below the lower limb of the longitudinal band, and not far 

 from it, is shown in Fig. 1 1 (cb), a portion of the circular band 

 with large flame-like cilia (or fused cilia ?). 



Fig. 12 shows the anterior view of the larva in the region 

 around the mouth. The whole of the digestive tract is seen 

 beneath the surface, passing as a cylindrical tube from mouth to 

 anus. The ciliated band p (as in the last figure) is seen to run 

 upwards on one side of the middle line, until just below the 

 mouth it crosses over and runs in a parallel course along the 

 opposite side of the middle line. The band o turns forward also 

 on each side of the middle line, but more to the left than the 

 band o, and at a higher level, and also crosses the middle line to 

 pursue a similar course on the other side. The mouth lies 

 between these two bands, the <?-band being pre-oral, the /-band 

 post-oral. The /-band crosses the middle line at an inner level 

 to the 0-band. The anterior lateral areas of the two sides are 

 shown at ac, all the tentacles on the left being thrown over 

 to one side. 



From the mouth the oesophagus runs upwards and forwards, 

 as seen in the figure, for a short distance, to join the upper end 

 of the cylindrical stomach. The latter is very long and runs 



