1910] HEALD & WOLF—STRUCTURE OF URNULA GEASTER 187 
diameter, being about 1.5 w. Fig. 7, which was drawn from fixed 
(chromacetic acid) and imbedded material from young specimens, 
might easily have been interpreted as representing a pseudoparen- 
chyma. After the dehiscence of the apothecium, the hyphae con- 
Stituting the wall enlarge rapidly to 3-6 times their diameter in young 
specimens, reaching a thickness of 4.5-9 » (fig. 8). At this stage it 
would seem almost impossible for even the most careless observer 
to interpret the structure as a pseudoparenchyma, since the hyphae 
are so large that even in dried specimens they could not be mistaken 
for cell walls. Even in the most compact part of the subhymenium 
the hyphae and intercellular spaces are easily distinguished (jig. 4). 
The asci are 700-800 » in length and 14-17.25 » in diameter. 
This is somewhat in excess of the measurements given for Urnula 
craterium,® the type specimen of the genus. The ascus is nearly 
uniform in diameter and shows a short characteristically curved 
basal portion. This character and the origin of the asci from the 
subhymehium is shown in fig. 4. The free end of the ascus is bluntly 
rounded and shows an apical pore which permits the rupture of the 
wall when the spores are expelled.. The eight continuous hyaline 
Spores are confined to the upper two-thirds of the ascus, and are 
arranged with their tips slightly overlapping, but in a single series. 
They are oblong-fusiform and distinctly flattened on one side, 
54-68 # long by 10-13 wide; each spore contains 3-5 prominent 
guttulae (fig. 5). Numerous branched septate paraphyses are present, 
which are uniform in diameter throughout (slightly less than 2 #) 
and do not show a terminal enlargement @s figured by KUPFER 
(1. c. pl. 8. fig. 4). 
Systematic position and relationship 
As a result of a comparative study of several species of Urnula 
and Geopyxis, KuPFER (l.c. 142) has made Urnula geaster Peck 
the type of the new genus Chorioactis. The basis for the separation 
is stated as follows: “That it is not an Urnula seems to me just as 
evident from its external appearance as from an examination of its 
tissues. A comparison of internal characters shows, however, that 
there is no possible relation with Urnula craterium. ‘The tissue is 
® Saccarpo, P. A., Sylloge Fungorum 8:549. 1890. 
