440 . Griffiths : Pyrexomvcktes 



recurved : asci cylindrical, contracted below, sessile, usually more 

 or less curved or inequilateral, 1 2-1 5 ji x 50-60 ft : spores 3-scp- 

 tate, constricted at the septa, fusiform, brown, 5-8 // x 16-20 n, 

 PL j66. / 7-p. 



On dead scapes and leaves o{ Allium brcvistylum in Big Horn 

 Mts., near Buffalo, Wyo., Aug., 1898. (Williams and Griffiths.) 



The method of development of the perithecia in this species is 

 of interest. The conidial hyphae usually protrude through the 

 stomata in tufts of 2-5, and the perithecia are developed as a 



^_ ^_ ^ I 



proliferation of the cells at their bases. At first the hyphae 

 arise directly from the hypodermal myceh'um which can be 

 easily seen In tangential sections, but the proliferation of cells at 

 their bases soon gives them the appearance of arising from a 

 pseudo-parcnchymatous mass of fungous cells. The hyphae are 

 carried upward by this mass of cells, and the stoma and surround- 

 ing tissues become much distorted. The hyphae appear to pro- 

 ' duce conidia for some time after the beginning of pcrithccial 

 development as shown in the figures. These, liowcver, finally 

 disappear before the perithecium becomes mature, and bristles de- 

 velop surrounding the central ostiolum. Unfortunately mature 

 material is rather rare, but the conidial and transitional stacres have 

 been collected in good quantity. 



A 



Pyrenophora Salsolae sp. nov. 



Perithecia aggregated, subepidermal, early erumpcnt, subglo- 

 bosc to flattened, black, carbonaceous, brittle, about 300 ft in diam- 

 eter, covered uniformly above with short, brown to black, septate, 

 slightly wavy fugaceous bristles : asci cylindrical, contracted below 

 into a short-stipitate base, 3-8-sporcd : spores one- or two-seriate, 

 ovate, muriform, 4-5-septate with two longitudinal septa, sliglitly 

 flattened, yellow, 6-1 i // x 20-26//. PL j66,f. jo-j^. ' 



The method of spore dissemination In this species is very inter- 



I 



esting. There is ne^ir the middle of the ascus a transverse mark- 

 ing which is usually plainly visible. Sometimes it is simply a 

 transverse line on the ascus wall, but more often it appears as a 



I 



spiral of i y^ turns. When pressure is put upon the cover glass, 

 the asci rupture on these markings, the top of the ascus shooting 

 out for some distance, leaving in its wake the spores more or less 

 deranged, but always in a long string imWlded in a gelatinous 

 matrix, which does not remain attached to them when they are 



