792 Thomas . — Notes on Cephaleuros . 
Figs. 4, 13, 14, and 17 with 3 mm. and comp. oc. 4. 
Fig. 10 with D. Zeiss and oc. 6. 
Figs, it, 12, 15, and 16 with D. Zeiss and oc. 4. 
Figs. 1-6 Ceylon form a. 
Figs. 7-9 Ceylon form P. 
Figs, io-ry Barbadoes form. 
Fig. 1. Ceylon form a. Early stages in development of discs, (<z) Diameter not more than 
o-oi mm. ( b ) Slightly older stage. Near the disc but not attached to it are hyphae of a Fungus, 
x 455- 
Fig. 2. Older disc. Transverse walls not yet formed. Striations in lower wall, x 455. 
Fig. 3. Specimen of older thallus. Transverse walls have formed and the loose posterior end 
of the radial walls is a prominent feature, x 455. 
Fig. 4. Mature lobed thallus of Ceylon form a, growing between two thalli of the P form. 
Nuclei present in the cells. Specimen shows the characteristic radial walls and mode of cell-division 
and growth, x 225. 
Fig. 5. Lobe of mature thallus seen from below, showing Fungal hyphae lying along the Algal 
walls. Connexions with free hyphae. X 535. 
Fig. 6. Section of mature thallus, showing hyphae cut transversely and obliquely, and striations 
in lower wall of Algal cells only, x 730. 
Fig. 7. Ceylon form P. Young stages, dark cell-walls, divisions already smaller in size, 
x 455- 
Fig. 8. Lobe of mature thallus, showing mode of growth, smaller cells than in form a. Note 
characteristic radial walls, x 365. 
Fig. 9. Section of Ceylon form P, showing thickened upper cell-wall, x 1,070. 
Fig. 10. Barbadoes plant. Small piece of thallus, showing mode of growth, young zoosporangium 
and development of hair at periphery, x 430. 
Fig. 11. Lobe of mature thallus, showing mode of growth, curved rhizoids in lower focus, 
thallus zoosporangium (uninucleate), and aerial hair, x 300. 
Fig. 12. Section of thallus and leaf of host, showing subcuticular position, development of 
rhizoids, and decay of cells of host, x 300. 
Fig. 13. Section of thallus, showing young zoosporangium embedded in the thallus, uninucleate, 
with dense cell-contents. Some of the cells show lamellose structure of the cell-wall. x 450. 
Fig. 14. Section of thallus with older multinucleate zoosporangium with thickened cell-wall, 
x 450. 
Fig. 15. Section of thallus with aerial sterile hair which has perforated its way through the 
cuticle. Hair with dense cell-contents and nuclei, x 300. 
Fig. 16. Section of thallus with aerial hair with swollen extremity and prominent nucleus. 
Young stage of fertile hair, x 300. 
Fig. 17. Section of thallus with aerial fertile hair more fully developed, a cell cut off at the 
extremity, x 450. 
