92 PROCEEDINGS OF THE AMERICAN ACADEMY. 



III. 



CONTRIBUTIONS FROM THE C-RYPTOGAMIC LABORATORY 

 OF HARVARD UNIVERSITY. 



XXL— NEW GENERA AND SPECIES OF LABOULBENIA- 

 CE^, WITH A SYNOPSIS OF THE KNOWN SPECIES. 



By Roland Thaxter. 



Presented November 8, 1893. 



In attempting some years since to obtain materials for a monograph 

 of* the Laboulbeniaceas, the writer did not anticipate that a fifth pre- 

 liminary paper would be reached before he felt in a position to publish 

 a general account of the family ; yet, however much the description 

 of so large a number of new forms without proper figures is to be 

 regretted, the delay in this respect seems fully justified by the essential 

 data which have been obtained during the past two years. It cannot 

 be doubted that the number of existing forms greatly exceeds the 

 total already known, but it seems safe to assume that the basis of 

 knowledge now available is sufficient to illustrate, at least in a general 

 way, the more important characteristics of the group from a morpho- 

 logical as well as a systematic point of view. The promised mono- 

 graph will therefore be published as soon as the necessarily numerous 

 plates can be completed; and since a sixth preliminary paper will, if 

 possible, be avoided, a summary of the known genera and species is 

 appended for convenience of reference, together with a very brief note 

 concerning certain matters relating to the general morphology and 

 development of the group. 



The writer's observations, based upon an examination of several 

 thousand specimens illustrating more than a hundred species and more 

 than twenty genera, appear to warrant the following conclusions. 



The LaboulbeniaceEe, while showing no signs of any non-sexual 

 mode of reproduction, are characterized by a well marked sexual type, 

 closely resembling that of the simpler Floridese. They are ascomy- 

 cetous fungi, producing usually four, sometimes eight spores in asei 



