Arthur: Uredinales of Costa Rica 125 



Aecia 



Aeciospores largely globoid (18-26 by 24-29 /a) 



Peridial cells long (48-67 fx) 



Peridial cells short (24-42 fx) 



U. venustus 

 U. maculans' 



Aeciospores largely oblong (19-26 by 25-37 fx) 



Peridial cells distinctly verrucose 



Peridial cells appearing smooth 



U. Cestri 

 U. cestricola 



38. Uromyces Hariotanus Lagerh. sp. nov. (on Acanthaceae) 

 Thyrsacanthus strictus Nees (?), San Ramon, Jan. 13, 1916, 

 III, 416; Tres Rios near Cartago, Jan. 17, 1916, III, 440. 

 These collections agree exactly, even to the appearance of the 

 host, with a collection made by G. von Lagerheim, on Acan- 

 thaceae, obtained at Guamampata, Prov. Chimborazo, Ecuador, 

 August, 1 89 1, and distributed by the collector under the name of 

 " Uromyces Hariotanus Lagerh. n. sp." The name does not ap- 

 pear to have been published. A description is therefore ap- 

 pended, using the Ecuadorian collection as the type, and retaining 

 the name, given by the collector in honor of the distinguished my- 

 cologist of the Museum of Natural History, Paris, recently de- 

 ceased. 



Telia amphigenous, numerous, scattered, or sometimes 

 crowded, usually round, 0.2-1 mm. across, early naked, pulver- 

 ulent, chocolate-brown, ruptured epidermis evident ; teliospores 

 ellipsoid, 19-21 by 26-32 /x, rounded or obtuse at both ends; 

 wall dark cinnamon-brown, thick, 3-4 /x, thickened into a light 

 brown or colorless umbo at apex, 6-9 fx, closely to moderately 

 and noticeably verrucose ; pedicel colorless, one and a half times 

 length of spore, fragile. 



39. Uromyces Hellerianus Arth. (on Cucurbit aceae) 



Cayaponia attenuata Cogn., San Jose, Jan. 10, 1916, ii, III, jpp, 

 A long-cycle species, not uncommon in tropical North America, 

 of which the initial stage is unknown. 



40. Uromyces pressus Arthur & Holway sp. nov. (on 

 Carduaceae) 



Vernonia Deppeana Less., San Jose, Jan. 3, 1916, II, iii, 361' 

 (type); El Alto near Cartago, Jan. 16, 1916, II, 432 ; Car- 

 tago, Jan. 20, 1 91 6, II, 450. 



Vernonia sp., San Ramon, Jan. 13, 191 6, II, III, 413, 



