SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. 869 
Palaeomyces Asteroxyli, Kidston and Lang, n.sp. (Pis. II and III, figs. 20-28. 
Slide No. 2525.) 
Non-septate, branched hyphse ; branches sometimes recurved ; ranging in 
diameter from 4 m to 20 n. Vesicles borne terminally on some of the branches ; 
not separated from the hypha by a wall ; attaining a diameter of about 80 m. 
Occurs between the cells of the inner cortex of the rhizome and of the axes 
intermediate between rhizomes and shoots of Asteroxylon Mackiei. Also in the 
more or less decayed tissues of the cortex, and occasionally on the surface of the 
rhizome in the matrix. 
Locality. — Muir of Rhynie, Aberdeenshire. 
Horizon. — Old Red Sandstone. (Not younger than the Middle Division of the 
Old Red Sandstone of Scotland.) 
Palaeomyces Horneae, Kidston and Lang, n.sp. (PI. Ill, figs. 29-35. 
Slides Nos. 2531, 2532.) 
Non-septate, branched hyphse often with brown walls, attaining a diameter of 
10-15 n ; present in the intercellular spaces of the tissues and also in the adjoin- 
ing matrix, from which entering hyphse may be traced. Spherical or oval resting- 
spores ; about 100 n in diameter ; with, at maturity, moderately thick, brown 
walls not differentiated into layers. 
Occurs in relation to the surface, and between the cells of some rhizomes and 
the basal regions of stems of Hornea Lignieri. 
Locality. — Muir of Rhynie, Aberdeenshire. 
Horizon. — Old Red Sandstone. (Not younger than the Middle Division of the 
Old Red Sandstone of Scotland.) 
Palaeomyces vestita, Kidston and Lang, n.sp. (PI. IV, figs. 36-38. 
Slide No. 2454.) 
Fine non-septate hyphse about 3 ^ in diameter ; bearing spherical resting -spores 
about 45 m in diameter ; wall of spore thin, but frequently invested by a close 
covering of the slender hyphse. Similar spores of larger size are also met with. 
Occurs in decaying tissues, especially of stems of Asteroxylon. 
Locality. — Muir of Rhynie, Aberdeenshire. 
Horizon.- — -Old Red Sandstone. (Not younger than the Middle Division of the 
Old Red Sandstone of Scotland.) 
Palaeomyces Simpsoni, Kidston and Lang, n.sp. (PI. IV, figs. 45-4 7 . 
Slide No. 2568.) 
Characterised by the peculiar grouping of the stalked vesicles, which burst 
through the surface of a partially decayed stem in oval patches ; vesicles widen out 
