236 



THAXTER. — MONOGRAPH OF THE LABOULBENIACE.E. 



KEY TO THE GENERA OF LABOULBENIALES. 



In order briefly to summarize the genera thus far described, the following dichotomous key has been 

 prepared which indicates in a general way their supposed natural sequence, as far as this is possible in 

 such a summary, and includes a tentative separation of the more pronounced types which have been 

 designated by special names designed to suggest the conditions of isolation in the various genera or groups 

 of genera. It is not expected that this key will prove useful as a means of determining genera to anyone 

 who has not made himself familiar with the general conditions existing in the group and summarized in 

 the preliminary matter of this and the preceding Monograph. It will be observed that Distichomyc.es, 

 although at maturity it possesses free simple antheridia, is included among the Peyritschiellaceae, where 

 it rightly belongs, and that also Hydwphilomyccs is included in the second section, of Ceratomycetineae, 

 although its supposed antheridial cells are more or less clearly distinguished. The latter are, however, 

 merely corners, as it were, separated from the cells of the main appendage, and later appear to grow out 

 into sterile branches as in Coreomyces. Polyascomyces, Smeringomyces and Misgomyces, being of uncertain 

 affinities, and their antheridia being unknown, are assigned merely provisional places in the arrangement. 



1. 



2. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18. 



19. 

 20. 



21. 



90 



Antheridia specially differentiated cells or groups of cells. 



Antheridia compound, the antheridial cells endogenous, arising from 

 one or more intercalary cells and discharging into and from a com- 

 mon chamber (eventually free in a compact group in Distichomyccs) 



Individuals unisexual. 



Perithecia arising from a primary vertical or oblique axis. 

 Perithecia arising from one or more secondary axes springing from 

 the subbasal cell. 



Individuals hermaphrodite, sterile appendages unicellular, subtended 



by black constricted septa. 

 Antheridium a free branchlet from the receptacle. 

 Antheridial cells discharging through a common pore. 

 Antheridial cells becoming free in a compact group. 

 Antheridium wholly or partly adnate to the receptacle. 

 Cells of the receptacle in tiers above the basal cell. 

 Perithecia wholly free. 



Subterminal tier of the receptacle bearing paired antheridia. 

 Subterminal tier bearing a single antheridium at one side. 

 Perithecia imore or less adnate to the distal portion of the receptacle. 

 Antheridium anterior at the base of the perithecium. 

 Antheridium near base of appendages; two cells superposed above 

 foot. 



Antheridium as in 18, three cells above foot. 



Individuals hermaphrodite, sterile appendages multicellular, sub- 

 tended by black constricted septa. 



Individuals hermaphrodite, sterile appendages absent or without 

 black subtending septa. 



Antheridium discharging between four terminal appendiculate cells. 



LABOULBENIINEiE 80 



PEYRITSCHIELLACE.E 



Dimorphomyceteae 



Dimeromyces 



D imorphomyces 



Rickiese 



Rickia 



Distichomyces 

 Peyritschielleae 



Dichomyces 

 Peyritschiella 



Limnaiomyces 



C ' Jiitonomyces 

 Hydmomyces 

 Enarthromyceteae 



Enarthromyces 



Monoicomyceteae 



35 

 7 

 6 



20 

 11 

 10 



18 



16 

 15 



18 

 19 



21 



25 



