1916] Gilkey: A Revision of the Tuherales of California 289 



record of studies made of young forms in this genus, but it seems evi- 

 dent from mature ascoear{)s that, as in Peziza, the opening from the 

 hymenium comes about as the result of development. Considering 

 these resemblances, as well as those of Hydnocystis to Geopora and 

 through the line to Tuhcr and Piersonia — described in the introduc- 

 tion to this paper — its arrangement as a connecting link between the 

 Pezizales and the higlier Tuberales seems justifiable. 



Hydnocystis calif ornica sp. nov. 



Plate 29, fig. 9 



Ascocarp 1 cm., subgloboso, light to very dark brown, completely 

 closed, enveloped in brown, septate, branched mycelium ; surface 

 divided into mostly hexagonal areas, 1.5 mm. in diam., forming bases 

 of pyramidal projections ; gleba white ; tissue pseudoparenchymatous 

 through verrueosities, cells 12-16/x in diam., walls of outer cells slight- 

 ly thickened ; occasional cells developing as septate hairs ; pseudoparen- 

 chymatous tissue changing within to hyphae of same diam. as outer 

 cells, these becoming much narrower toward hymenium ; latter lining 

 cavity of ascocarp and fonned of regular palisade of asei and para- 

 physes ; asci cylindrical, somewhat constricted between spores, nar- 

 rowing to more or less definite stipe, 16-24 X 240;li; spores globose- 

 ellipsoid, smooth, 18-20 X 22-24/i,, 1-seriate; paraphyses slender, 4-6ju, 

 thick, generally length of asci but some projecting beyond at irregular 

 distances ; barely swollen at tip. 



Odor of caramel. 

 "Under Pinus, in sand, Ingleside, San Francisco Co., Cal., May 2, 



1903." No. 121, \].C. Col, type. N.L.Gardner. 



The three species of Hydnocystis described in Sylloge Fungorum, 

 vol. VIII, p. 876, are distinguished from our species as follows : 



H. piligcra by globose spores 32-35/x, in diam. ; 



H. arenaria by an opening to hymenium, size of ascocarp (reach- 

 ing the diameter of a chestnut), spore measurement (13-16 l)y 16- 

 19/*), and unpronounced odor; 



H. Thwaitesii by an opening to the hymenium. and spon^ slmpe 

 and measurements (13-16 by 16-19/*). 



There are other minor differences and all seem sufficient to separate 

 the species. 



H. Beccari, a later species founded by ]\Iattirolo, apparently differs 

 from ours in long-ellipsoid spores (24—27 by 15/t) and the presence of 

 an opening to the hymenium, though full descriptions of this species 

 could not be obtained. 



