i9H] THAXTER—NEW ZYGOMYCETES 365 



Selenodon from Hayti. 



distingu 



ceding species by its roughened nodding sporangia, smooth spores, which are 

 always solitary in the strain examined, and its slightly larger dimensions. It 

 is not impossible, however, that strains may occur in which two spores may 

 be produced in single sporangia, as in H . bisporale. 



Harvard University 



EXPLANATION OF PLATES XXVI-XXIX 



The figures have been drawn with a camera lucida and reduced in repro- 

 duction. The objectives used, Zeiss dry and Leitz water immersion, are indi- 

 cated in each case, and also the eyepiece numbers. 



PLATES XXVI AND XXVII 



Blakeslea trispora Thaxter 



Fig. 1. — Habit of moderately well developed group of heads bearing spo- 

 rangiola, showing a portion of the fertile hypha and its origin; D2. 



Fig. 2. — Group of heads denuded of sporangiola; D2. 



Fig. 3. — Single head with five sporangiola attached, showing corrugation 

 of branchlets below heads; water im. 4. 



Fig. 4. — The same in optical section, much younger; the spores not yet 

 mature in the sporangiola;. water im. 4. 

 • Fig. 5. — Sporangiolum mature, with adherent basal piece and containing 



spores; water im. 4. 



Fig. 6. — Normal three-spored sporangiolum; water im 

 Fig. 7. — Sporangiolum with four spores, the basal piec< 



adherent 



im. 4. 



Fig. 8. — Three-spored sporangiolum seen in optical section from above; 

 water im. 4. 



Fig. 9. — Four spores from sporangiola; water im. 12. 



Fig. 10. — Chlamydospores; D4. 



Fig. ii. — Fertile hyphae from the irregularly swollen end of which five 

 small sporangia were produced intermediate in character between sporangiola 

 and small normal sporangia; water im. 4. 



Fig. 12. — Fertile hypha with single head bearing more normal sporangiola; 

 water im. 4. 



Figs. 13-17. 

 Fig. 18.— Sc 



sporangia 



spores 



im. 12. 



Choanephora cucurbit aru m 



Fig. i8,4.— Two "conidia" showing thin membrane inclosing space below 



monosporangiolum; water im. 12. 



