—73- 



Species of Graphis and Arthonia were found in abundance. Almost every 

 tree trunk, especially if it was smooth, had, among other crustose forms, one or 

 more species of Graphis and Arthonia. Species thus far determined seem to be 

 the following: Arthonia complanata, A. didyma, Arihothelium macrotheca, Graphis 

 glaucoderma, G. scripta. 



Three species of Caloplaca were found, none of which are as yet satisfactorily 

 determined. Chiodecton sanguineum was found quite frequently. This pretty 

 bark Lichen delights 'to expose itself to the brightest sunshine. Although so 

 common, I found no specimen in fruit. Cyphelium tigillare was found. It was 

 not common. What little was found, was growing on bark. Diploschistes 

 scruposus was quite common. It grew only on rocks, or on the soil in between 

 the rocks, on slopes devoid of trees and exposed to the hot sun. On the sunny 

 slopes along the Latimer River trail, it was very common, being usually associated 

 with Coccocarpia pellila. 



Several species of Lecanora were found: Lecanora albella, L. varia, and L. 

 subfusca, the latter on rocks, the other two on tree trunks. L. varia also occurs on 

 dead wood. Species of Leptotrema, Thelotrema, Ocellularia, and Phaeotrema 

 were also common. Superficially they look much alike, and are all found on tree 

 trunks along the shady trails. They are readily recognized by the tiny punctures, 

 the ostioles of the apothecia, scattered all over the thallus. With some the tiny 

 openings are very minute, with others they are quite conspicuous. 



Another common crustose Lichen was Lopadium leucoxanlhum . It grew on 

 the bark of various trees, and in various situations, generally, however, more or 

 less sunny ones. Microihelia thelena was found on our trip to Green River, on 

 trees, at 3500 feet altitude. I failed to find it at the higher elevations. Several 

 species of Pertusaria were found. Some grew on rocks in the bright sunshine, 

 others on trees. Most of them have not as yet been satisfactorily determined. 

 Pyrenula mamillana was another common Lichen found on tree trunks. It was 

 at its best, however, at slightly lower altitudes than at Cinchona, at Green 

 River, 3500 feet altitude, and at Cl>de River, 4000 feet altitude. Lecidea, too, 

 was represented, but none of the species found have as yet been identified. 

 Lastly, Verrucaria calciseda must be mentioned. One was sure of finding this 

 wherever there was an outcrop of limestone. 



Epiphyllous Lichens 



I now come to a very interesting type of Lichens, the Epiphyllous Lichens. 

 How many of these were found, I am not yet prepared to say, very few of them 

 having been as yet determined. In this connection, I must state that their 

 study, as also the study of all tropical American Lichens is attended with much 

 difficulty. The literature is hard to get hold of, and considerable trouble is en- 

 countered in having one's material verified. However, progress is being made, 

 and although much time is being consumed, the work will finally be accomplished. 



My concept of an epiphyllous Lichen was considerably changed when I began 

 their study. Here in this wonderful Lichen country, almost any Lichen may be- 



