22,2 Shaw: Merrillosphaera africana 209 



5. The largest, or only, pair of gonidia is about in the middle 

 of the coenobium. 



6. The additional gonidia are smaller and in the back of the 

 coenobium. 



7. When four gonidia are not present, absent pairs or mem- 

 bers are commonly represented by abortive or vestigial gonidia. 



8. When two pairs of gonidia are present there is sometimes 

 a rudimentary third pair between the members of the first pair. 



9. The sexual coenobia are of three kinds; bisexual, female, 

 and male. 



10. Asexual coenobia and sexual coenobia of the different kinds 

 may be produced by the same mother in any combination. 



11. In the bisexual coenobia the androgonidia are few and 

 smaller than the oogonidia. 



12. In the bisexual coenobia the androgonidia occupy positions 

 like those of the gonidia in asexual coenobia ; that is, two are on 

 opposite sides of the middle of the coenobium and the third, 

 with the fourth if there be one, is in the back part of the coeno- 

 bium. 



13. The androgonidia divide at about the time of birth of the 

 coenobium and form platelets of sperms. 



14. The female coenobia are like the bisexual, but without 

 androgonidia. 



15. The oogonidia are decidedly smaller than the gonidia. 



16. The androgonidia are smaller than the oogonidia. 



17. The male coenobia contain large numbers of androgonidia 

 that divide at about the time of birth of the male coenobium or 

 afterward. 



18. The antheridia are platelets of sperms. 



From the forms with six and those with eight gonidia the 

 following points appear : 



19. Forms occur with two pairs of gonidia that are nearly 

 alike in size. 



20. In forms with six gonidia the second pair is in the middle 

 and its members alternate with those of the first pair. 



21. In forms with eight gonidia the fourth and smallest pair 

 is at the back and alternates with the third pair. 



22. The bisexual coenobia sometimes have four antheridia dis- 

 tributed around the middle of the coenobium and one or more 

 farther back. 



23. The platelets of sperms sometimes take the form of shallow 

 cups. 



