Classification. 99 



sometimes the lateral braucTies are entirely absent, 

 when the fungus has been described as a Miicor. In 

 other examples, the lateral branches are well de- 

 veloped and bear sporaugiola, but when the large 

 terminal sporangium is absent, this form has been 

 described as a new genus, Melidium. 



Thamnidmm verticillatum, Van Teigh. (figs. 33 — 35). 



Minute ; sporangiferous hyphas erect, branched ; 

 sporangium at apex of primary hypha globose, in- 

 crusted with lime ; columella cylindrical ; branches 

 verticillate, rather long, twice dichotomous near the 

 end, branchlets spreading, ending in minute, globose, 

 smooth sporaagiola, with a minute, plano-convex colu- 

 mella ; spores similar in the two forms of sporangia, 

 spherical, hyaline, 5-6 fi. 



Thamnidiiim verticillatum^ Van Tiegh. Ann. Sci. 

 Nat. ser. vi. vol. iv. p. 376, pi. 13, figs. 84 — 89; Sacc. 

 Syll. vol. vii. n. 715. 



On horse dung. Rare. 



Forming minute tufts, 4 — J in. high. The develop- 

 ment varies as in Tliamnidium elegans ; sometimes 

 the terminal large sporangium is suppressed, at other 

 times the branches are absent, and when present the 

 whorls vary from one to three. All these forms may 

 often be found in the same tuft. 



Rhizopus, Ehr. 



Hyphasma stolonif erous, straight or flexuous, giving 

 off fasciculate, slender branched hyphse from the under 

 side, at those points corresponding to the origin of 

 the fasciculate sporangiophores on the upper side, 

 white, becoming blackish ; sporangiferous hyphae 



H 2 



