Saprophytic Fungi of Eastern Iowa. i8i 



a direction inward and forward, and so divide the surface 

 into a series of symmetrically arranged quadrangular pits; the 

 ridges of the second system are sometimes not quite contin- 

 uous on opposite sides of a ridge of the first system, so that in 

 some cases the pits in a given row stand opposite the broken 

 ridges separating the pits in a contiguous row. 



The foregoing description applies to cast of the interior. 



Known only from casts found in Niagara limestone at Ma- 

 quoketa, Iowa. 



Bucania cyclostoma, n. s. 



PLATE I., FIGS. 2 a, b. 



A larger and more robust shell than the preceding, with 

 volutions at first transversely elliptical in cross section, but 

 gradually changing form and gradually expanding toward the 

 circular aperture. Surface unknown, except that there are 

 indications in the cast of a median dorsal groove; distinguished 

 from other species of this genus by its size and shape, for par- 

 ticulars of which the reader is referred to the figures. 



Found associated with preceding species in Niagara lime- 

 stone at Maquoketa, Iowa. 



THE SAPROPHYTIC FUNGI OF EASTERN IOWA. 



T. H. McBRIDE. 



On page 34 preceding, reference was made to certain plates 

 which should serve to illustrate some of the structural pecul- 

 iarities of the plants herein discussed. The plates Nos. IV. 

 and V. accompanying the present issue are intended to accom- 

 plish this purpose. On Plate IV., Figures 3, 4 and 5 illus- 

 trate the Basidiomycetes (p. 32). Figures 3 and 4 represent 

 the genus Agaricus, " trama tilamentose," and Figure 4 of 

 Rtcssula, " trama vesiculose," both as defined on page 34. 



To the white-spored Agarics already described we add the 

 following species identified since the issue of Bulletin No. i : 



