324 University of California Publications in Botany [Vol. 6 



arrangement of the venae externae. As described, those of the latter 

 species converge at one point, or at several outward-opening hyphal 

 strands at the base of the ascocarp. No mention is made of furrows, 

 though Tulasne's figures (1851, pi. VI, fig. 2) would indicate that they 

 are present, but if present there is evidently no relation between them 

 and the external openings of the veins. Since the venae externae of 

 our plants open into fissures which are strongly marked, and which 

 may occur upon any part of the ascocarp, it seems best to retain T. 

 candidum as a distinct species until more extended data for the Euro- 

 pean material can be secured. 



Tuber (Oogaster) lignarium (Hk.) comb. nov. 



Plate 30, fig. 25 



Terfeziopsis lignaria Hk., Proc. Cal. Acad. Sci., 3(1 ser., vol. 1, no. 8 (1899), 

 p. 279, pi. XLIV, figs. 23a-23c. 



Ascocarp brown, 1.5 cm. in diam., subglobose, somewhat furrowed, 

 surface smooth, gleba white, veins variable in size, conspicuous ; corti- 

 cal tissue pseudoparenchymatous, of very small, irregular, thick- 

 walled cells, changing somewhat abruptly to subcortex of compact but 

 mostly unconnected hyphae ; thickness of peridium, 320-360/x ; venae 

 internae and tissue between asci compact, of generally unconnected 

 hyphae, but latter tissue pseudoparenchymatous in places ; hyphae 

 4— 6/x. ; venae externae few, variable in size but generally very wdde at 

 opening and at various places in ascocarp, filled with loose, tangled, 

 branching hyphae, these often breaking away, leaving long canals 

 through interior of ascocarp ; asci long-stipitate, semi-globose and more 

 or less cylindrical, 40-52 by 60-72/x, 2-, 3-, or 4-spored, spores light 

 brown, globose-ellipsoid to globose, 20-32ju,, surface covered wath slen- 

 der spines with recurved tips, 46yu, in length. 



"Among oaks in sandy pasture, Auburn, Placer Co., Calif., June." 



No. 206, Hk. Col. Type. 



This is probably the species examined by Harkness and described 

 under Terfeziopsis lignaria, the globose or ovoid spores with recurved 

 spines being characteristic ; but the measurements in the material 

 which T examined do not agree with the recorded Harkness measure- 

 ments, and venae externae, though few, are conspicuous. These per- 

 lijips open to the surface regularly in furrows, but so little material 

 is available for study that this point cannot be accurately determined. 

 Since venae externae are present, and all other characters are typic- 

 ally those of Tuber, the species has been placed under that genus. 



