178 RESEARCHES ON FUNGI 



diameter or about one-half the diameter of the subsporangial 

 swelHng, shrinking on drying after discharge and becoming acutely 

 pointed ; columella very bluntly conical or rounded (when removed 

 from a discharged sporangium its edge is turned inwards toward 

 the axis), greyish, distinctly darker than the subsporangial swelling. 

 Spores ellipsoid, singly almost colourless but yellow in mass, 

 5-0-6-0 X 3-0-3-8 [i.. 



On horse dung, Winnipeg, Canada, and, according to a communi- 

 cation from the late Dr. Roland Thaxter (who observed the species 

 forty years ago but did not describe it), more frequently on sheep 

 dung, at Boston, U.S.A. 



Easily distinguished from all other species of Pilobolus by its 

 decidedly umbonate sporangium and its minute elhpsoidal spores. 

 With a hand-lens one can readily make out the acutely-pointed 

 umbonate shape of the diied discharged sporangia when these are 

 seen in lateral view, 



Latin Diagnosis 



Pilobolus umbonatus, sp. no v. Hyphae sporangiiferae 3-9 mm. 

 altae, e trophocystide terminah v. intercalari ovaU v. napiformi 

 solitaria v. in hypha crassa repenti sparsa oriundae. Stipes fihformis, 

 circa • 1 mm. diam., sursum sensim latior. Vesiculum suhsporangiale 

 elHpsoideum, 0-65 mm. longum, 0-46 mm. latum, circa medianam 

 partem latissimum. Sporangium eximie umbonatum, plus minusve 

 conicum, 0-23 mm. diametro, arescendo acutius evadens, columella 

 obtusissime conica v. convexa, cinerea, quam vesiculum obscuriore. 

 Sporae minutae, ellipsoideae, dilutissime luteolae, ferme achroae, 

 5-0-6-0 X 3-0-3-8 [i. 



Hab. in stercore equino, Winnipeg, Canada, atque (sec. htt, 

 Thaxteri) in stercore ovino a.pud Boston America e boreahs. 



Remarks on the Pilobolidae. — At my request Mr. W. B. Grove 

 has prepared for this Volume a systematic account and an arrange- 

 ment of the Pilobolidae. I have sought to assist him by providing 

 the necessary illustrations and by placing at his disposal the results 

 of my studies of Pilobolus longipes, P. Kleinii, P. umbonatus, found 



