1916] Gilkey: A Revision of the Tuherales of California 327 



thickened than outer; venae internae much branched, broadened at 

 ang'les, varying in width but mostly sh^ider, of compact liyplial struc- 

 ture simihir to subcortex, ])ecoming pseudopareiichymatous in i)laces ; 

 asei borne in distinct large "nests," generally irregularly bent or 

 variously shaped by inward extending branches of venae internae ; 

 asci generally long-stipitate, ci-owded, club-shaped, more or less de- 

 formed, 64-72 by 80-1 ()4/x, separated by fascicled, swollen-tipped para- 

 physes, 1-4-spored (generally 4-spored) ; spores globose, 22-36/x, yel- 

 low or brown, minutely alveolate, walls of alveoli half as wide as 

 alveolar cavities, 10-14 across diam. ; spores irregularly arranged in 

 ascus. 



"Beneath Ceanothus, Auburn, Placer Co., Calif., Mav." 



No. 183," Hk. Col. Type. 

 "In forest, Auburn, Placer Co., Calif., June." 



No. 201, Hk. Col. Type P. scahrosa. 

 "Under vegetable humus in sandy ground. Auburn, Placer Co., Calif., 

 May. " No. 1 89, Hk." Col. Type Hydnoholiffs c.renvatum. 



"Under pine trees in sandy soil, Towles, Placer Co., Calif., May." 



No. 44, Hk. Col. Referred to Pachyphloeus ligericus. 



This species is characterized by very large areas of hymenium 

 which cause the colored dots in the gleba mentioned by Harkness 

 (1899, p. 275), by narrow venae internae, generally 4-spored ascus, 

 and small ascoearp. Apparently, too, the venae externae of this species 

 are much shorter than those of P. hispora, and do not form the long 

 canals described by Fischer for that species (1908, ])p. 149-154), 

 though this point has not been determined satisfactorily for the reason 

 that the Harkness material is more or less granular at the present 

 time, and perfect sections have not been obtained. 



Harkness separated his two species upon the characters of asco- 

 earp color and spore measurement. Nothing in regai'd to the former 

 can be determined from the alcoholic material, luit in the specimens 

 sectioned and examined, absolutely no difference can be found in spore 

 size. Tn ])oth, the size varies fi-om 22-36/x, those from 30-36/x pre- 

 dominating. Evidently some error occurred in recording the Hark- 

 ness measurements, for these do not agree with his. Uiuler the num- 

 bers 189 and 44 of the Harkness collection, named respectively Hydno- 

 holites cxcavatum and Fachyphloeus ligericus (Harkness, 1899, p. 266 

 and p. 269) were discovered material of Piersonia. Tt is impossible 

 to tell from the descriptions of the two species mentioned whether or 

 not the plants examined by Harkness are the ones now found under 

 the same numbers. His description of Hydnobolites excavafum with 

 cavernous gleba and eight-spored asci woidd indicate that another 



