I)a\ KNi'oin — CiistaUII I- 



PLATi:*VIll. 



^''ig. T'J. Sagittal section of an ailnlt polypide. Tlio lophopliorc has been onntteil. 



Outlines with camera lucida. Nuclei put in free haiui. X 175. 

 " To. Sagittal section of huil. St^ige XIV. Tiie margin of colony to loft. 



* Ectodermal cells derived from neck of polypide. x ."jyo. 

 " 74. Nearly horizontal section of a IhkI a little older than that sliowii in Fig. 



73. The plane of section passes obliquely upward and forward. Tiie 



tentacles are cut at different heights, x .j90. 

 " 7;'). Transverse section of lophophore arms befort; separation. Tlu- coiniectiiig 



band, lajih.', is reduced to threads. Tlie polyjiide has already evagi- 



nated. The section figured, is the seventh from the distal end of the 



arms, — about 40 m distant. X 390. 

 " 76. Transverse section of lophophore arms innnediately after separation. The 



tentacles arising from can. cr< .'' were previously fused, x 300. 



