IOWA ACADEMY OP SCIENCES. 
153 
The chlorophyll bearing parenchyma can be divided into 
two parts. First, large parenchyma cells surrounding the 
bundles; these consist of rather large cells somewhat roundish 
in shape; second, elongated cells in one or more rows around 
the first. 
SPOROBULUS CRYPTANDRUS. 
The epidermal cells in this species do not differ from those 
described for S. heterolepis. The bulliform cells (b) are some- 
what larger than those in the first species, usually two or three 
quite large cells and two smaller on each side. One or two 
groups of bulliform cells occur between a large mestome 
bundle, and, as in S. heterolepis, these do not occur between 
the last two bundles. 
The carene (c^) has one mestome bundle (m) which is open on 
both sides. It is somewhat larger than other mestome bundles. 
The leptome (1) and hadrome (h) are separated from each other 
by thick- walled parenchyma (p^); two rows of thick parenchyma 
occur around the leptome. 
The mestome bundles are of three types: First, those open 
above and below; second, those open above only, and third, 
such as are entirely closed. Those of the third type are 
more numerous than others. One mestome bundle is 
entirely closed and at the side of the leaf, those of the third 
type alternate with those of the second and first types. The 
second type is more numerous than the first. Ten bundles 
occur on each side of the carene. The mestome bundles of the 
third type are usually found between two groups of bulliform 
cells. The chlorophyll bearing parenchyma (c. b. p.) is about 
as in S. heterolepis. The leptome in this species differs from 
leptome in S. heterolepis in not being depressed on the upper 
side. 
The stereome (st) is found on the lower side of all bundles, 
and also upon the upper side of all bundles except those of the 
third type. The cells of the sterome are not so thick walled as 
in S. heterolepis. 
The mesophyll consists of elongated cells in one or two 
rows around each mestome bundle. There seems to be mesophyll 
connecting the bundles beneath the unclosed parenchyma. The 
unclosed parenchyma is found in one or two rows around the 
bulliform cells in contact with the mesophyll. 
SPOROBOLUS HOOKERI. 
The epidermal cells (e) of this species are small, thick 
walled and uniform in size, they are more roundish than in 
