1916] Gilkcij: A Revision of the Tuheralcs of California 321 



from short-ellipsoid to globular, the reticulations are not regular in 

 form, and the spores measure 8-20/a instead of 5-9ja in diameter. 



T. californicum, so far as collected, differs from descriptions of 

 T. Magnatum in size, our species rarely found as large as 2.5 em., while 

 T. Magnatum is said to reach 8 cm. and sometimes more. The ascl of 

 T. Magnaixnn are described as only 40-55 by 60-70/x; the spores as 

 short ellipsoid instead of globular, tlie ascocarp with a distinct base 

 which is absent in ours; and no mention is made of pubescence. The 

 only pubescent Sphaerotuher (aside from T. puherulum which is some- 

 times so placed), listed in Saccardo's Sijlloge Fungorum, is T. Mou- 

 geotii, which differs in its description from T. californicum in l)eing 

 tuberculate, having granulose gleba, 2-4-spored asci, and yellow spores 

 measuring 30-40ju,. 



Tuber (Oog*aster) candidum Ilk. 



Plate 27 



Tuher candidum Hk., Proc. Cal. Acad. Sci., 3d ser., vol. 1, no. 8 (1S99), p. 



274, pi. XLV, figs. 32a-32&. 

 Tuber CaroU Hk., non Bonnet., Proc Cal. Acad. Sci., 3d ser., vol. 1, no. 8, 



p. 274. 

 Tuher Eisenii Hk., Proc. Cal. Acad. Sci., 3d ser., vol. 1, no. 8, p. 275. 

 Txiber olivaceum Hk., Proc Cal. Acad. Sci., 3d ser., vol. 1, no. 8, p. 275. 



Ascocarp liglit brown to reddish brown, reaching 2 em. in diani., 

 semi-globose, nearly even, with one furrow, or several generally con- 

 nected furrows, mostly on one side, furrows sometimes united into 

 circles forming ' ' eyes ' ' of different color from general ascocarp sur- 

 face, u.sually pink in young specimens; surface of ascocarj) smooth 

 with small papillae about furrows, or whole surface divided into 

 minute low polygonal areas, occasional colorless septate hairs on sur- 

 face, particularly at or near mouths of venae externae ; veins mostly 

 large, whitish, consiucuous, converging at furrows; cortical tissue 

 minutely and compactly pseudoparenchymatous, outermost cells some- 

 times lengthened laterally and more or less separated, forming short, 

 knotted, laterally extending hairs or loose network similar to tissue 

 of venae externae; pseudoi)ai'('nch>'iuatous layer changing within to 

 subcortical layer of laterally elongated hyphae 4-6jli thick ; thickness 

 of peridium 200 360/a ; venae internae of loosely or more or less com- 

 ])actly arranged liy])liae; tissue between asci generally similar, but in 

 some cases becoming more or less pseudoparencliymatous ; venae ex- 

 ternae fiHed with loosely interwoven, branched hyphae, 4-6/i, thick, 

 opened into furrows of ascocarp surface; asci long or short stipitate, 

 generally ovoid, easily separated from hymenial tissue, 44—52 by G4- 

 80/x, l-7-s]iored ; spores brown, exceedingly varial)le in shape from 

 globose-ovoid to long, generally more or less conspicuously })ointed at 



