Colonies on PDA at first white, then deep gray in center, periphery remains white with wavy irregular appearance, becoming brown at one month, usually somewhat restricted with turf height about 0.3-0.4 cm. Sporangiophore 8-15 µm in diam., up to 0.4 cm in height, hyaline to brown, sympodially branched. Fertile branches circinate, bearing a single sporangium or a single sporangium and a sterile spine. Sterile spine light in color and cut off by a septum near the branching place. Many shorter sporangiophores present with alternate arrangement of sporangia without spines. Sporangia globose, sometimes dorsiventrally flattened, typically 30-48 µm; at first white, then dark gray, becoming brown with age. Sporangial wall persistent when breaking. Columellae pyriform, usually constricted in the center or conical, measuring 20-25 × 23-30 µm. Much of the sporangial wall remains attached. Sporangiospores globose, mostly 5.0-6.5 µm, smooth.
Specimens：
D01301, from pig dung, Yuan-li, August, 1995.
Habitat：
null
Distribution：
Cosmopolitan
References：
Hesseltine CW. and Fennell, DI. 1955; Zycha, H. et al. 1969; Ho, HM.1995.
Provided：
H. M. Ho
Note：
Circinella muscae is reported as new to Taiwan. This fungus is recognized by the presence of sterile spines on sporangium-bearing branches. A closely related species is C. mucoroides. The differences between these two species are:1. sporangiophores of C. mucoroides are twisted in open corkscrew turns, but those of C. muscae are not. 2. C. mucoroides has many sterile spines unaccompanied by sporangia on branches but in C. muscae, spines and sporangia are almost always together on the same branch.
Phylum：Zygomycota >> Class： Zygomycetes >> Order： Mucorales 
BCRC Number：