HELVELLEAE. 457 



Verpa. Pileus drooping, regular, margin entire, 

 thimble-shaped. 



Leotia. Pileus fleshy, discoid; spores obliquely 1-2- 

 seriate. 



Cudonia. Pileus fleshy, discoid ; spores very long and 

 slender, arranged in a parallel fascicle in the ascus. 



Mitrophora. Surface of pileus furnished with stout 

 anastomosing ribs bounding deep, elongated pits ; 

 lower part of pileus free from stem. 



** Pileus adnate throughout to the stem, 



| Spores obliquely 1—2-seriate in the ascus. 



Morchella. Surface of pileus furnished with stout, 

 anastomosing ribs bounding deep, irregular pits. 



Gyromitra. Surface of pileus covered with rounded, 

 variously contorted folds. 



Mitrula. Pileus subglobose or clavate, surface even. 



tf Spores long and slender, arranged in a parallel fascicle in 



the ascus. 



Spathularia. Pileus flattened, running down the 

 stem for some distance on opposite sides. 



Vibrissea. Pileus capitate ; spores remaining attached 

 to the surface of the pileus for some time after 

 escaping from the asci. Aquatic. 



B. Spores coloured. 

 Geoglossum. 



