[Vol. 13 

 232 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



hymenium and in those places effused, small, thin, closely adnate, 

 somewhat membranaceous-fleshy, ivory-yellow when growing, 

 fading to white in the herbarium, even, not cracked, the margin 

 continuous with the sterile mycelium; in section 100-150 \l 

 thick, not colored, composed of suberect, branching, densely ar- 

 ranged and somewhat interwoven hyphae 3-33^ y. in diameter, 

 short-celled, occasionally nodose-septate; no gloeocystidia; ba- 

 sidia simple, cylindric, 27 X 3J^-4J^ p., with 4 knob-shaped 

 sterigmata; spores hyaline, even, 6-8 X 3^-43^ [*., copious; 

 some imbedded spores present. 



Fructifications 5-10 mm. long, 1-2 mm. wide. 



In thick bark of coniferous logs on side walls of tunnels made by 

 a bark-boring beetle. Idaho probably. 



C. cultum is one of the species which should be considered in 

 connection with the fungous flora of burrows of bark-boring 

 insects. The term " ambrosia fungi" has been used for some 

 other fungi growing in such places. The type specimen of 

 C. cultum is scanty but well fruited. The species has not been 

 received from any source as growing on the exterior of bark or 

 wood. 



Specimens examined: 

 Idaho: probably Idaho but only general locality stated, J. R. 



Weir, comm. by W. G. Farlow, type (in Mo. Bot. Gard. Herb., 



44655). 



42. C. rubellum Burt, n. sp. 



Type: in Burt Herb. 



Fructifications broadly effused, adnate, thin, somewhat mem- 

 branaceous, small pieces separable when moist, vinaceous-fawn, 

 becoming wood-brown in the herbarium, even, not waxy, the 

 margin thinning out; in section 120-500 y. thick, not colored 

 when thin but somewhat colored in thick fructifications and then 

 stratose, with the hyphae arranged longitudinally and crowded 

 together parallel with the substratum in each stratum, more 

 loosely interwoven towards the hymenium, 2J^-3 y. in diameter, 

 not incrusted, rarely nodose-septate; no gloeocystidia; spores 

 copious, hyaline, even, 6-9 X 5-6 y., flattened on one side, with 

 a small apiculus on the flattened side near the base. 



