V. The Sixteen Tentacle Stage . 



'v'Tiile the eiglit tentacles of the first cycle are still 

 quite short, eight tentacles of a second cjrcle make their ap- ; 

 pearance in the intervals between the tentacles of tlie first. 

 Fig. 10. The animal shown in this figure was, two days before, 

 a swimming planula-like larva. It is interesting as an exam- 

 ple of how the irregular increase in the number of tentacles, I 

 Lhat is so common, is brought about. T'.vo tentacles cf the 

 first cycle have become bifurcated, so that in each of these j 

 places there are two tentacles where, if the larva were regu- 

 lar, there would be but one. 



Figs. 32 and 36 are from a series of cross sections of a 

 larva perhaps a little older than tliis one. Figs. 32, 33 and 

 34 are consecutive : The first two show the entodei^nal connec- 

 tion between two gastric pouches at the base of an interradial 

 tentacle. In Fig. 34 the septum is complete. Fig. 35 is 

 the second one from this and shows the gastric pouches opening 

 into the central stomach. A section of the stem is seen in 

 Fig. 36. The septa do not extend below the expanded part,v\'hat 

 we may call the calyx 'of the scyphi stoma. There 



is a very slight depression in the peristome in the region of 

 each septal muscle, but no true septal funnels appear. Fig. 32. 



- 35 



