190 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
but such was not the case. Hence it may be assumed that the cottony 
veil and porose-cellular hymenium are normal characters, or, if origi¬ 
nally monstrosities, that they have become fixed and permanent. 
In studying the development of the hymenium of well established 
genera of the Hymenomycetes we observe definite habits or laws of 
growth which are invariable under normal conditions. Thus in the 
Agaricaceae the originally smooth hymenium becomes broken up by 
descending folds or lamellae of equal thickness which are radially 
placed and occur at fixed intervals; in Polyporus the downward 
growth of the hymenium forms tubular pores of approximately regu¬ 
lar diameter and arrangement; in Daedalea there is a lack of regu¬ 
larity in the original arrangement of the folds on the hymenophore, 
but these folds, once started, then grow on with considerable regularity 
and result in the formation of variously shaped spaces and passages, 
but not of closed chambers. This definite law of growth may be 
overthrown in a given species as the result of parasitism or other 
conditions of environment, as may be observed in almost any artificial 
culture of a Hymenomycete; the result is sometimes a deformity like 
the anastomosing gills of Agaricus campestris reported by Patouillard, 
or the cellular-porous form of Polyporus which Peck named Myria- 
doporus. In distinction to these regular laws of growth Lentodium 
appears to be a genus without any well defined law in the development 
of its hymenial region. The plates arise from the hymenophore 
without definite order, thus recalling Daedalea; but, unlike the latter, 
they do not grow downward regularly when the position has once 
been determined, but branch and anastomose to form the cellular- 
porous hymenial layer characteristic of the genus. As has already 
been pointed out, these peculiarities are due to the diffuse habit of 
growth of the trama which forms the false veil. Such an interpretation 
removes this fungus from the category of abnormalities, and, until 
further investigation shall have adduced proof to the contrary, it 
should, in the opinion of the author, be ranked as an autonomous 
species. 
Systematic position of Lentodium .— Although this genus agrees 
with the Hymenomycetes in most respects, particularly as regards 
its development, yet the appearance of the mature fructification 
seems to suggest gasteromycetous affinities. The thick stratum of 
closed spore chambers bounded by the pileus above and the thickened 
veil below strongly resembles the gleba of certain Hymenogastrineae; 
