Shaw: Merrillosphaera africana 215 



Plate 3 



14. An immature asexual coenobium of the same form of Merrillos- 



phaera africana as those shown in Plate 2, figs. 8 and 13, and 

 Plate 4, figs. 21 to 26, inclusive. It measures 370 by 390 ft and 

 contains two advanced embryos with open phialopores, two very 

 young embryos, and two gonidia. The young embryo that is 

 the left member of the lower pair is 2-celled, that which is the 

 right member of the upper pair is 4-celled. The gonidia measure 

 about 50 by 52 ft and 50 by 55 ft, the inequality of the dimensions 

 indicating preparation for division. Specimen 18. X 100. 



15. A nearly mature sexual coenobium of the typically ovoid form. 



The dimensions are 500 by 585 ft, and the reproductive bodies 

 are twenty-seven oospores. Specimen 12. X 100. 



16. An oospore of the same coenobium, slightly out of focus, and the 



overlying somatic cells. The outside diameter of the spore is 

 40 ft. The diameters of the somatic protoplasts in sharpest 

 focus are a little more and a little less than 5 ft. This spore 

 is the one in the left side and nearest the front of the coenobium 

 and is out of focus in the preceding figure. Specimen 12. 

 X 400. 



17. Another sexual coenobium of the same form. It measures 470 



by 520 ft and contains thirty-one oospores that are not quite 

 mature. A little above and to the left of the center an empty 

 antheridial site may be seen. Specimen 13. X 100. 



18. Four oospores from the same coenobium. The somewhat wavy 



appearance of their walls is due to shadows of overlying somatic 

 cells. Diameters of spores about 41 ft. Specimen 13. X 400. 



19. An asexual coenobium of a 6-gonidiate form, of which a younger 



one is shown in Plate 4, fig. 20. It was about 350 by 420 ft in 

 breadth and length. The bulging of the sides is probably due 

 to cover-glass pressure. The left daughter contains two grand- 

 daughters and four gonidia in pairs. The right daughter con- 

 tains a granddaughter, an embryo, and two gonidia. In each 

 daughter the nearest granddaughter contains four gonidia in 

 pairs. Specimen 26. X 105. 

 Plate 4 

 . 20. A younger asexual coenobium of the same 6-gonidiate from of 

 Merrillosphaera africana and from the same source as the one 

 shown in Plate 3, fig. 19. It measures 230 by 290 m and contains 

 four daughters and one gonidium. Behind the right larger 

 daughter there is a smaller one. The gonidium, 54 m wide, 

 is paired with the smallest daughter. The left daughter con- 

 tains three gonidia. Specimen 25. X 105. 



21. An asexual coenobium from the same source as the specimens 



shown in Plate 2, figs. 8 and 13, Plate 3, fig. 14, and Plate 4, 

 figs. 21 to 26. It contains two daughters and two very young 

 embryos. The daughters contain gonidia proportioned and^ 



22. A sexual coenobium of th 



oogonidia. Specimen 23. 



