Davknport. — Cristatella. 



PLATE VIII. 



Fig. 72. Sagittal section of an adult polypide. The lophophore has been omitted. 

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

 " 73. Sagittal section of bud. Stage XIV. The margin of colony to left. 



* Ectodermal cells derived from neck of polypide. X 390. 

 " 74. Nearly horizontal section of a bud a little older than that shown in Fig. 



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



tentacles are cut at different heights, x 390. 

 " 75. Transverse section of lophophore arms before separation. The connecting 



band, loph.', is reduced to threads. The polypide has already evagi- 



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



arms, — about 40 n distant. X 390. 

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



tentacles arising from can. crc." were previously fused, x 390. 





