Gkiffitus : Pvrexomycetes 4-13 



Grevillea i8 : 



^pJt 



Cke. This species also may be a Dothidca. It certainly ap- 

 pears to have its asci produced in stromatic cavities without peri- 

 thecia the same as the species here described ; and the spores 

 have the typical unequal septation of the genus DotJiidca when 



r 



young, but they become more nearly equal when mature. In the 

 general appearance of asci and spores there is but little differ- 

 ence between this species and the one which is described above. 

 A specimen in the Ellis Herbarium from Dr. Harkncss shows the 

 spores to be larger and the asci nearly twice the width at the base. 

 These are the only differences in the microscopic characters. The 

 method of growth is, however, decidedly different. The stromatic 

 areas in my species arc two to three times as large, prominently 

 erumpent and surrounded by the lacerated remains of the ruptuied 

 epidermis ; while in the other case the epidermis is unruptured 

 although the specimens appear to be as fully developed as mine. 





Pleospora aquatica sp. nov. 



Perithecia scattered, ^subglobose to hemispherical, i40-i8o/< 

 in diameter, flattened when dry, subepidermal, remaining cov- 

 ered, membranous, black and smooth with flat indistinct ostiolum : 

 asci cylindrical-clavate, curved, and often bent into a u shape, short- 

 stipitate, without paraphyses, 22-29 // x 95-125 /i : spores oval, 

 10-12 (i X 28-30 //, slightly flattened, with 5 transverse and 2 to 

 4 longitudinal septa, constricted at all transverse septa and sur- 

 rounded by a gelatinous hyaline covering which is prolonged into 

 a short thick blunt appendage at either end. PL 366. f. 2j-2^. 



This species was collected at Aberdeen, S. D., in May, 1896, 



on dead stems of Rlcocharis palnstris under water. The pond in 



I 



which the collection was made, had been filled with artesian well 

 water together with that obtained from natural drainage to a depth 

 of not less than a foot since the previous season. I first dis- 

 covered the fungus in April when it was immature. About a 

 month later I visited the same locality again and found an abundance 

 of it in the best condition possible. The pond contained from 2 



K 



months and the culms of 



the previous year upon which tlic fungus grew were entirely sub- 



m e rged . 



1 



Columbia UMVKRsrrv, i July, 1899. 



