1904] THAXTER: NOTES ON MYXOBACTERIACEAE 4°09 
than the number of described forms would indicate; but as these 
need more careful examination and culture than it has been pos- 
sible to give them, no additional species are here included; 
attention being merely called to the fact that a number of forms 
of the ‘‘rubescens” type, having spore masses of various colors, 
as, for example, magenta red, various shades of orange or yellow, 
milk-white, etc., should in all probability be eventually separated. 
Among the new forms described below, Chondromyces catenu- 
/atus is a most interesting contribution to the group, since it 
presents a new type of cyst formation, and still further illustrates 
the remarkable resemblance which these pseudofructifications 
bear to the spores and sporophores of some of the higher 
Fungi imperfect. As has been previously pointed out, the differ- 
ences that are so marked in some of the species result largely 
from secondary impulses which, influencing the ultimate rod- 
masses at the period of cyst formation, produce*in the mature 
cyst the distinctive form which in many cases is the most easily 
recognized and sometimes the only visible specific character. In 
C. catenulatus the conditions are unusually complicated for the 
reason that the ultimate rod-masses, having become more or less 
cylindrical, elongated, and sparingly branched, instead of respond- 
ing to a single impulse in order to form a single ultimate cyst, 
is affected by a series of such impulses which cause the rods to 
stream together from opposite directions toward numerous suc- 
cessive points in the continuity of the mass; each point forming 
the nucleus of adistinct cyst. The ultimate masses thus become 
converted into chains of cysts united by slender isthmuses of 
variable length formed from the shriveled, tough, gelatinous 
secretions left behind by the moving rods (figs. 3-4), the whole 
pseudofructification thus assuming the form of a main axis or 
cystophore from the summit of which arise and diverge numerous 
series of spore-like cysts cohering in sparingly branched chains. 
Of the three forms which have been referred to Polyangium, 
none corresponds very closely to the type, and the copious 
matrix of gelatinous material which surrounds the cysts in P. 
vitellinum is either wanting, or at least not as well differentiated. 
Of the new forms, P. septatum and P. compositum are both further 
