Davenport. — Cristatella. 



PLATE VII. 



Figs. 61-G3. Three vertical right-and-left sections of same polypide passing from 

 posterior end anteriorly. About Stage XIV. (Fig. 73, Plate VIII.) 

 X 390. 



" 61. Section through lophophore arms, showing their fusion, loph.', and the 

 position of the ring canal, can. crc.', can. crc." 



iC 62. Section just posterior to anal opening, showing openings of lophophoric 

 pockets. 



" 63. Section through ganglion, showing early stage in formation of lopho- 

 phoric nerve, parts of the ring canal, and young tentacles. 



" 64. Cross section of lophophore arm, near termination of young nerve, at 

 place marked 64, Fig. 71. X 1000. 



" 65-67. Three successive sections through end of lophophore nerve in re- 

 gions marked 65, 6(5, and 67, Fig. 71. These figures are from the 

 same individual as Fig. 64, but from the opposite lophophore arm. 

 x 1000. 



" 68. Vertical right-and-left section through ganglion of an individual slightly 

 younger than Fig. 63, showing origin of cornua by outgrowth of the 

 walls of the ganglion, with an extension of the lumen of the latter. 

 X 600. 



" 69, 70. Longitudinal sections of two stages in the development of a tentacle, 

 Fig. 70 being the younger. X 390. 



" 71. Section through ganglion and growing lophophore nerve. Stage XIV. 

 X 490. 



