The genus Helicocephalum was erected by Thaxter 1 in 1891 to make provision for a fungus that he found in a laboratory culture on carrion, and accordingly described under the appropriate binomial H. sarcophilum. In the brief discussion close resemblance to a large Mortierella or Syncephalis was pointed out, the similarity obviously applying more especially to the scattered distribu? tion of the plant on the substratum, to the small diameter and aseptate or rarely septate condition of the vegetative hyphae, to the pronounced differentiation of the simple erect sporiferous hypha, and to the presence on the latter of rhizoid-like supporting basal attachments. Features distinguishing the fungus from any of the known genera of Mucoraceae were recognized in the char? acter of the unusually large brown spores, as well as in their de? velopment through maturation of segments resulting from the insertion of septa at intervals in the helicoid distended terminal por? tion of the fertile hypha. Although more than four decades have elapsed since the appear? ance of Thaxter's publication, the mycological literature of the intervening period would seem to offer no record of any encounter at first hand either with Helicocephalum sarcophilum or with any form sufficiently similar to be recognized as a congener. It may therefore not be unprofitable to set forth the main characteristics of such a congeneric form that made its appearance early in 1933 on rather old maize-meal agar plate cultures originally planted with decaying rootlets. On the mycelia of various species of Pythium that first extended themselves through the substratum had become superimposed a mixture of plant and animal life including an abundance of bacteria, nematodes of various species evidently feeding on the bacterial slime, several fungi preying on the nematodes, 1 Thaxter, Roland. On certain new or peculiar North American Hyphomycetes. II. Bot. Gaz. 16: 201-205. 1891.
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Feb 1, 1936
W J Dowson + 1