ON A NEW SPECIES OF CORYMOR PHA FROM JAPAN. 163 



excepting that the constituent cells have become slightly taller and 

 more numerous. The oldest development alstage obtained is represent- 

 ed in fig. 6. It measures about 2.5 mm. in length, and shows essenltialy 

 the same feature as the adult ; six gonosomal prominences, the upper 

 hydranth-septum and the lower fenestrated membrane, have come 

 into more distinct existence ; the longitudinal canals have much 

 increased in number (at least 8), and the most proximally situated 

 papilla; have assumed a filamentous shape. The first indication of the 

 increase in thickness is seen at this stage in the epithelium of the 

 future free-cell forming struture. Fig. 8 represents a portion of a 

 sagittal section through the hydranth of the oldest bud ; in it the 

 epithelium in question is seen as a layer two-cells thick, which is 

 sharply differentiated from other cells of the endoderm by its deeply 

 staining capacity. 



Zoological Laboratory, 



Higher Normal Scliool, Hiroshima. 

 May, 1909. 



