* 
CERTAIN SPECIES OF Mucor 293 
from dung (presumably squirrel), once from decaying tomato, 
rabbit dung, and dog dung, respectively. Nos. 7, 9, 14, 19, 22, 
25, 28, 31, 32, 33, and 60. Nos. 14 and 22 were collected by 
Messrs. K. Duncan and E. B. Mains, respectively. 
Mucor abundans is characterized by the oval to pyriform col- 
umella, the variable—globose to short-elliptical—spores, and the 
color of the turf (smoke gray tinged drab). It is related to Mucor 
griseo-lilacinus, but differs from it in the color of the turf, the 
oval to pyriform columella, the variable—globose to short ellip- 
tical—spores, and the absence of the lilac tinge in the columella 
and hyphae. It is also related to M. hiemalis (sense of Hagem), 
from which it differs in the shape of the columella and in the shape 
and size of the spores. 
Mucor abundans grows 40 mm. tall on rolled oats, 30 mm. tall 
on corn meal, 25-35 mm. tall on rice, with or without the forma- 
tion of buff to yellow line around edges of surface of rice, and 
9-18 mm. tall on grapefruit. It ferments dextrose, but does not 
oxidize tyrosin. 
- 5. Mucor CIRCINELLOIDES Van Tiegh, Ann. Sci. Nat. Bot. VI. 
1:94. 1875 
Forming on bread a dense, pale smoke gray (Ridgway) turf, 
1-3 cm. tall; sporangiophores 8-16 pw in diameter, tall and short, tall 
forming a turf 2-3 cm. tall, and short attaining only 1-2 mm. 
in height, tall sporangiophores with long or short branches, short 
sporangiophores more profusely branched with short and often 
circinate branches, always terminating in a sporangium and with 
a septum above the point of insertion of branch; sporangia globose, 
of tall sporangiophores, 50-70 » in diameter (extremes 43-80 yu), 
of dwarf sporangiophores, 14-35 u in diameter, at first yellowish, 
becoming brownish gray at maturity; sporangium wall deliquescent 
in sporangia borne on tall sporangiophores, rupturing or persistent 
in sporangia of dwarf circinate sporangiophores, leaving a basa 
membrane; columella free, globose to oval, 31-43 X 31-39 
(extremes 20-51 X 18-43 u), tinged grayish; spores uniform, sub- 
globose to oval, 3-5 X 3-4 or 3-5 in diameter (extremes 8 
X 6-8» in diameter); chlamydospores and oidia in and on sub- 
stratum, chlamydospores 20 X 12 m; zygospores not found (species 
heterothallic). 
This species is characterized by the tall and short (often cir- 
cinate) sporangiophores, the subglobose to oval columella, and 
