280 



Mycologta 



further progress was made, but in 191 3 a very active phase of the 

 work was initiated by Stevens and has steadily progressed up to 

 the present time. During 191 3-1 5 Stevens made extensive col- 

 lections of fungi and accumulated a large amount of material 

 which is deposited at the herbarium of the University of Illinois. 

 He has studied his collection in collaboration with some of his 

 students, and they have published a number of papers on the 

 pyrenomycetes '(16, 21, 28, 29, 30, 31, 32, 33, 34, 35) in which a 

 great number of new species have been described. Whetzel and 

 Olive spent the spring of 1916 in the island collecting rusts and 

 other parasitic fungi. A few of the pyrenomycetes of their col- 

 lections have been described by Fitzpatrick (13, 14) and Seaver 

 (25), and recently a list of all. of them was published by the 

 writer (6). A third extensive collection, consisting chiefly of 

 lichens and ascomycetes, was made by Fink in the winter of 

 191 5-16, but nothing has been published on it, excepting a pre- 

 liminary note by him (12). However, a set of his collections has- 

 been sent to the writer, and a further study of them will certainly 

 disclose a number of interesting forms. The pathologists at the 

 Insular Experiment Station at Rio Piedras, P. R., have given a 

 generous part of their time to the collection of fungi and their 

 specimens are deposited at the Station Herbarium. A number of 

 their pyrenomycetes have been sent to Seaver for identification. 



Stevenson's "Check List of Porto Rican Fungi" (36), which 

 is a compilation of all the species previously reported and widely 

 scattered in literature, appeared in 19 18. It constitutes a starting 

 point for the study of the fungous flora of the island. This paper 

 is rapidly going out of date, however, and the necessity for its 

 revision is felt. 



The writer, having become interested in the study of the pyreno- 

 mycetes, spent the summer of 1920 in the island collecting inten- 

 sively on this group. Also the collections of Whetzel and Olive, 

 Stevens, Fink and those of the Insular Experiment Station have 

 been available to him. A close study of these has brought out a 

 sufficient number of interesting facts to warrant the publication 

 of this paper. It represents an attempt toward a more complete 

 understanding of the insular forms of the group. 



