Fink: Distribution of Fungi in Porto Rico 59 



groups to which special, attention was directed were not, of 

 course, secured in large numbers. The ascomycetes were very 

 abundant, and areas a few rods square, which at first looked 

 most unpromising, often held the collector for hours, taking the 

 fungi from bark, leaves, rocks, pebbles, and soil. 



Regarding the fungous flora in general, the rusts, the imperfect 

 fungi, the black Perisporiaceae, the crustose lichens, the py- 

 renomycetes, and the Hysteriaceae abound. Foliose and fruti- 

 cose lichens are frequent but scarcely common. Fleshy dis- 

 comycetes were seen infrequently ; but these are difficult to detect, 

 unless one is giving sole attention to them. Agarics are by no 

 means common. Pore fungi were seen more often ; but these 

 are scarcely frequent, excepting a few species. Mycelia of the 

 Erysibaceae were seen occasionally, but diligent search failed to 

 reveal any evidence of fruiting. The crustose, often incon- 

 spicuous Graphidaceae are the most common fungi ; and the even 

 more obscure Arthoniaceae are perhaps next in abundance, though 

 so inconspicuous as to be seen infrequently, except by one well 

 acquainted with the group. 



A question about which little seems to be known is whether 

 lichens occur commonly on rocks in the tropics. The rocks were 

 found to bear quite as abundant and perhaps as varied an assem- 

 blage of lichens as do similar rocks in temperate regions. At 

 lower elevations the flora of the rocks was peculiar and doubt- 

 less tropical, but from 2,000 to 5,000 feet the general appearance 

 of the lichens was about the same as that commonly seen in 

 temperate regions. It is not easy to secure lichens growing on 

 rocks, especially in hot climates ; and the failure to get more 

 lichens from tropical rocks evidently does not signify that the 

 plants are absent from such substrata. 



Perhaps the thing that would impress the average mycologist 

 most is the absence of the white Ersibaceae in fruit and the great 

 abundance of the black Perisporiaceae in fruited condition. One 

 accustomed to collecting in temperate regions will instinctively 

 examine each white mycelium, expectant of that which seldom 

 if ever results, the finding of perithecia. The white mycelia are 

 rare and are seldom if ever fruited, while the black ones are 

 abundant and are well fruited, except in the desert regions. 



