102 A. Barclay — A Descriptive List of the Uredineas [No. 2, 



The peridium is very resistant, and when emptied of the orange 

 red aecidiospores is white. It ruptures along the summit or ridge when 

 ripe to allow the exceedingly numerous aecidiospores to fall out. It 

 consists mainly of two layers of cells (in some parts of three) very 

 firmly adherent to one another, by the interlocking of the prominent 

 spines which cover them externally. The walls of these peridial cells 

 are 4/x thick, and the cells themselves measure when moistened from 

 28 x 20 to 44 x 29/x,, or on an average 38 x 41^. 



The aecidiospores are formed in very long rows, those towards the 

 basidia being separated from one another by clearly denned intercalary 

 lamellae. They are oval orange red bodies, with thick epispores, beset 

 with numerous and prominent spines, which doubtless aid in their aerial 

 distribution. The dry spores measure on an average 24'3 x 17'9/x, and 

 when moistened 25'4 x 17'9/x. After lying 24 hours in water they 

 measured 26'4 x 19'6/a on an average. I never succeeded in getting 

 these spores to germinate in cultivations, although I have tried various 

 fluids. 



Spermogonia. These are of the usual structure ; but are very large 

 and deeply set. 



Remarks. — This species must, I think, be considered different from 

 Aec. Pini (Willd) Pers., as the aecidiaare very different in shape and size. 

 Whilst the species I have described has large flat peridia, from 5 m.m. 

 to 1 cm. in length and 2'5 to 3'5 m.m. in height, those of A. Pini are co- 

 nical or cylindrical and 2 to 2'5 m.m. in height. Moreover, whilst the 

 aecidiospores of the latter are 30 to 34 x 20 to 22/a those of the Simla 

 species are 26 — 24 x 19 — 17/x. 



2. Aecidium brevius, nov. sp. 



On Pinus excelsa, Wall. 



This is an almost ecpially abundant Aecidium, though less promi- 

 nent than the above, the peridia being much smaller. It is, I believe, 

 a distinct species. I have only met with it on the needles and never on 

 the stem. It is tnai'kedly later in appearing to observation than the 

 former. The aecidia begin to appear early in April, and increase in 

 numbers to June. The needles of this host are not altogether annual, 

 though a great many are shed annually, and those attacked by the 

 parasite are apparently always so shed, as after July no vestige of the 

 aecidia remains. New needles begin to emerge from their scaly coverings 

 towards the end of April, and are full grown in July to August. These 

 new needles are never found attacked. 



The aecidia are like those of the above species, elongated, flattened, 

 orange red bodies, but much smaller (fig. 2, PI, III). One of ordinary 



