and on a new Species o/* Protococeus. 435 



Fig. 5. Tlie same, a gi-oup of six individuals of the largest size, which 

 was separated from cue of sixteen individuals, showing the 

 manner in which the stipes is attached to the central cell, which 

 here appears also with the central area and its surrounding cells : 

 a, bilobate form of individual ; b, c, d, showing gradation of the 

 outer profile of the cell from concave to convex, following the 

 more or less robust state of the individual, purposely drawn in 

 this way to point out how different the form of an iudi\ idual 

 cell of the same Sorosfrum may be under different circumstances, 

 even in the same species. 

 Fiff. 6. The same, group of large individuals from which several baby 

 groups were developed, showing seven individuals still tilled 

 with gonimic contents {a), two empty collapsed ones (b h), and 

 five baby groups (c), all of which have (for particular examina- 

 tion) been more or less separated by pressure from their original 

 gi-ouped arrangement. Baby groups ^-GOOOtlis inch in diameter, 

 individuals l|-6000tli inch broad : four groups eliminated in 

 parent cells respectively, c; and the other consisting of a group 

 apparently of eight individuals free (that is, with no enveloping 

 cell), f/. 

 Fig. 7. The same, the foregoing gi-oup with the large individuals only, viz. : 

 — those which still retained their gonimic contents (a) and those 

 which were collapsed and empty {b b) ; the contents of the former 

 eliminated to show their rounded, altered forms and more or less 

 atrophied spines, respectively (c, c, &c.) ; also tAvo more empty 

 and collapsed individuals, making in all four from which the 

 baby groups had been eliminated ; lastly, the fragmental remains 

 of some cells (d) which may or niaj' not have been originally 

 developed in this group, which thus seems to have belonged to 

 the sixteen-cell division. 

 Fig. 8. The same, baby gi'oup to compare with that developed from the 

 sponingium, fig 1 ; size of baby group 3-6000ths inch in diam., 

 individuals H -(5000th inch broad each. 

 Fig. 9. The same, form and size of assumed sporangium, filled with go- 

 nimic contents of a deep dark sea-i^reen colour, like that of the 

 Surastruin-^xow^, 13-GOOOths inch in diameter : a a, gelatinous 

 capsule about 3-GOOOths inch thick ; b, proper coat of spo- 

 rangium. 

 Fig. 10. Omococcus elongatus, n. sp., single cell, 4-()000ths inch in diam., 

 filled with gonimic contents including nuclear (I-*) vesicle, show- 

 ing also the peculiar conical extension of the cell-wall. 

 Fig. 11. The same, in binary division ; 12, binary division, with subdivi- 

 sion of conical extension preparatory to quadruple division ; 

 1-'?, quadruple division ; 14, eight-cell division ; lo, sixteen-cell 

 division ; 10, cell-division in four tetrahedral groups of four 

 cells each, sportive form; 17, irn'gnlar sixteen-cell division; 

 18, eight-cell division, with partial extension of the gonimic 

 contents into (dl the radii; 19, eight-ctU division, extension of 

 the gonimic contents throughout in one radius ; 20. eight-cell 

 division with complete extension of the gonimic contents 

 throughout each radius. The last four groups, including the 

 radii, G-o400ths inch in diameter. 



M 



