1917] DUNN—DUMONTIA 465 



PLATE XX 



Fig. 30. — Similar carpogonial branch; terminal cells binucleate; Xiooo. 



Fig. 31. — Section of fifth cell of a 6-celled carpogonial branch; 26 chro- 

 matophores distributed on the cytoplasmic net; X1400. 



Fig. 32. — Six-celled mature carpogonial branch showing carpogonium 

 lying near cell 3; Xiooo. 



Fig. 33. — Similar to fig. 32; cell 3 is binucleate; Xiooo. 



Fig. 34. — Six-celled carpogonial branch showing coiled trichogyne; X 1000. 



Fig. 35. — Seven-celled carpogonial branch showing trichogyne reaching 

 almost to surf ace of thallus ; Xiooo. 



Fig. 36.— Six-celled carpogonial branch showing carpogonium in contact 

 with cell 3; cell 1 contains 3 nuclei; cytoplasm in cells 4, 5, and 6 is beginning 

 to disintegrate ; X 1 000. 



Fig. 37. — Six-celled carpogonial branch showing much coiled trichogyne 



reaching almost to surface of thallus; Xiooo. 



Fig. 38. — -Six-celled carpogonial branch showing carpogonium in contact 



with cell 3 which is much enlarged, nucleus of which is preparing to divide; 

 Xiooo. 



Figs. 39, 40. — Base of carpogonial branch, and trichogyne projecting 

 beyond surface of thallus; Xiooo. 



Fig. 41. — Base of carpogonial branch (cells 1-4), and trichogyne project- 

 ing beyond surface of thallus; 8 spermatia attached to trichogyne; Xiooo. 



Fig. 42. — Carpogonial branch; 3 sporogenous filaments arising from cell 2; 

 Xiooo. 



Fig. 43. — Carpogonial branch and auxiliary cell branch connected by 

 sporogenous filaments; auxiliary cell branch consists of 6 cells; X700. 



PLATE XXI 



Fig. 44.— Auxiliary cell branch; sporogenous filaments lying over cell 4; 

 Xiooo. 



Fig. 45. — Auxiliary cell branch; sporogenous filament fused with cell 3; 

 Xiooo. 



Fig. 46. — Auxiliary cell branch; cells 2 and 3 binucleate and a super- 

 numerary cell present ; X 1000. 



Fig. 47. — Three-celled auxiliary cell branch; Xiooo. 



Fig. 48.— Five-celled auxiliary cell branch; nucleus of cell 4 preparing to 

 divide; cell 1 contains 3 nuclei; Xiooo. 



Fig. 49.— Auxiliary cell branch consists of 4 cells; cell 2 binucleate; 

 Xiooo. 



Fig. 50.— Four-celled auxiliary cell branch; cells 1, 3, and 4 binucleate; 

 Xiooo. 



Fig. 5 i .—Four-celled auxiliary cell branch showing dense cytoplasmic 

 contents of cells; 7 chromosomes and colorless nucleolus in nucleus of cell 3; 

 Xiooo, 



