_General Information_: Another name for _X. hypoxylon_ is ‘Candle-snuff fungus’. Other club-shaped ascomycetes include members of the genus _Geoglossum_ (already mentioned p. 172) and members of the genus _Cordyceps_. Plate 69. ~Cordyceps militaris~ (St Amans) Link, the ‘Scarlet caterpillar fungus’, produces orange-red or orange, minutely roughened fruit-bodies up to 50 mm high, which grow on larvae and pupae of moths buried in the soil. It is not infrequent late in the autumn in pasture land. ~C. ophioglossoides~ (Fries) Link produces long (up to 100 mm high) yellow stemmed, dark and rough headed fruit-bodies growing on the subterranean fungus _Elaphomyces_--see p. 244. ~C. capitata~ (Fries) Link also grows on fungi beneath the soil surface but has a rounded head. _Leotia lubrica_ Persoon the ‘Gum-drop fungus’ is similarly coloured but grows on soil under trees and is gelatinous. It grows in autumn and is quite common and in fact more related to the Discomycetes than to _Cordyceps_. _Illustrations_: _X. polymorpha_--F 7^{d}; LH 47; NB 147⁶. _X. hypoxylon_--F 7^{e}; LH 47; NB 147⁵. _C. militaris_--LH 48. F. SPECIALIZED HABITATS (i) Fungi of dung and straw heaps ~Bolbitius vitellinus~ (Fries) Fries Yellow cow-pat toadstool _Cap_: width 20-40 mm. _Stem_: width 2-5 mm; length 30-60 mm. _Description_: Cap: chrome-yellow or lemon-yellow when young, paling with age at margin to become cinnamon-buff, bell-shaped but rapidly expanding to become plane or slightly umbonate, smooth, viscid but soon drying; margin striate then radially grooved, often split and the whole cap soon collapsing. Stem: slender, whitish, cream colour to pale yellow, at apex covered in small, white floccose scales but downy at the base, fragile and soon collapsing. Gills: adnexed or free, cinnamon-buff, thin and crowded. Flesh: yellowish, very thin and lacking distinct smell. Spore print: rust-brown. Spores: long, yellow-brown under the microscope, ellipsoid with a very distinct germ-pore about 13 × 8 µm in size (11-15 × 6-9 µm). Facial cystidia: rare, balloon-shaped. Marginal cystidia: swollen, flask-shaped with a variable, elongate neck. _General Information_: This fungus is common on horse droppings or other manures, but it may also be found amongst grass in pastures and in sand-dunes, and gardens on piles of rotting grass stems or straw. It is easily recognised by the colour and rapid expansion of the cap and the sudden collapse of the whole fruit-body. ‘Vitellinus’ means yolk of an egg and refers to the persistently bright yellow cap-centre, so obvious even when the fruit-body collapses. This collapsing is not one of autodigestion as described for members of the genus _Coprinus_. It is variable both in size and habitat, and I even have records of the fungus growing within herbaceous stems. _Illustrations_: LH 153; WD 80⁶.