Affinities of British Tuber aceae. 257 
or broadly elliptical, translucent brown, with large, shallow reticulations, 1-4 in an 
ascus, 40-50 p, or 45 X 60 p. 
Most nearly allied to T. mesentericum, Vitt., from which the present species 
differs in the larger, globose or subglobose spores, and the less tortuous dissepiments. 
The ridges of the network of the epispore often give off blind ends projecting into 
the polygons. 
Type specimen in Herb. Kew. examined. 
‘Closely allied to T. aestivum , Vitt., but easily distinguished by the odour; 
it differs also in the general form, being much more regular, and the warts smaller, 
and in the existence of a basal cavity prolonged into the substance of the fungus, 
which is thus very light compared with T. aestivum. It shrinks very much in drying. 
The sporangia [asci] have much longer stalks than in T. aestivum. The sporidia 
closely resemble those of that species, but are slightly longer compared with their 
width, and have somewhat shallower cells. It ranges from the size of a walnut 
to that of a hens egg. Odour bituminous and very strong of horseradish.’ Berk. 
Hab. In deep sand. 
Distr . Britain. 
Tuber foetidum, Vitt., Mon. Tub., p. 41, pi. 1, fig. 8, and pi. 3, fig. 11 (1831) ; 
Tub, Hypog., p. 140, pi. 17, fig. 7 (1851); Corda, Icon. Fung., vi, p. 80, fig. 135 
(1854) ; Sacc., Syll., viii, p. 887 (1889); Chatin, La Truffe, p. 69 (1892). 
Ascophore irregularly globose, variously nodulose or lobed, smooth or minutely 
corrugated, brownish, 1 -5-3-5 cm. diam. Gleba whitish at first, becoming soft and 
of a reddish-brown colour, dissepiments whitish, rather thick, very much branched 
and anastomosing. Asci obovate or variable in form, 2-4-spored. Spores reticulated, 
mesh not very large, shallow, 27-36 x 20-30 p, brown. 
Smell and taste resembling that of rancid oil, with a suggestion of onions. 
Specimen from Vittadini, in the Kew herbarium, examined. 
Hab. Subterranean. 
Distr. Britain ; Italy. 
Tuber macrosporum, Vitt., Mon. Tub., p. 35, pi. 1, fig. 5 (1831); Tub, Hypog., 
p. 139, ph 17, fig. 8 (1851); Cooke, Brit. Fung., p. 739 (1871); Sacc., Sylb, viii, 
p. 887 (1889). 
Ascophore globose sometimes nodulose, covered with minute depressed warts and 
often cracked, blackish and spotted with rusty brown, 2-5 cm. diam. Gleba at first 
white, changing to purplish-brown or blackish, dissepiments numerous, mixed with 
finer dusky lines. Asci subglobose, with long, slender pedicels, 1-3-spored. Spores 
elliptical, brown, reticulated, mesh small, rather shallow, 50-65 x 35-40 p. 
Readily known by the large, elliptical spores. The network on the epispore is 
small-meshed, but the size and form of the openings are irregular. Smell strong, 
resembling onions. 
Specimen from Vittadini, in Herb. Kew., examined. 
Hab. Underground, under oaks, willows, poplars, &c., often in clay soil. 
Distr. Britain ; France ; Italy ; United States. 
Tuber excavatum, Vitt., Mon. Tub., p. 49, ph 1, fig. 7 (1831); Tulasne, 
Hypog., p. 144, ph 6, fig. 1, and ph 17, fig. 5 (1851); Cooke, Brit. Fung., p. 740 
