A CtenopJwran. 27 



minal lobes, and may be called the terminal plates, while the 

 four shorter lie nearer the transverse plane, and may be 

 called the lateral plates. 



As the eight ctenophoral rows approach the aboral pole, 

 each terminal pair become united at the margin of an aboral 

 crater-like depression, and form a single line which passes 

 down the wall of the depression in the plane of the first per- 

 radius. The four lateral rows, however, preserve their indi- 

 viduality until they have reached the deeper portion of the 

 depression. 



At the base of the depression is a small opaque spot, the 

 " sensory body" 



If each lateral ctenophoral row is followed orally, it will 

 be found, at its lower end, to change its character somewhat 

 abruptly. At this point, four long finger-shaped processes 

 will be noted which extend freely between the terminal 

 lobes. These processes are the " auricles" and they lie 

 interradially. Each auricle is somewhat flattened, its two 

 richly ciliated edges being directed one away from and one 

 towards the terminal lobe. The cilia of the first-mentioned 

 edge continue, orally, the line of the true ctenophoral row. 

 This continuation extends from the free end of the auricle 

 aborally along the edge that is turned towards the terminal 

 lobe until it has reached a point near the " sensory body ' 

 midway between the neighboring terminal and lateral rows. 

 At this point it unites with a much larger fringe that has 

 extended aborally along the inner surface of each terminal 

 lobe from near the sagittal end of the mouth. There are 

 four of these large fringes. 



Internal Anatomy. The opening of the mouth has 

 been already observed. It leads into an oesophagus, which 



