316 Wisconsin Academy of Sciences, Arts, and Letters. 



of Ciyptoearpus bushes also occur here covered with Passiflora 

 foetida. Occasional trees of Hippomane Mancinella also grow 

 on this area. In many places along the west and south sides of 

 the bay the growth consists of low bushes, with a considerable 

 number of Cereus sclerocarpus and Opuntia myriacantha trees 

 scattered among them. 



After leaving the immediate vicinity of the shore, at the north 

 end of the bay, one encounters dense jungles of xerophytic 

 plants which extend inland a mile or more to the base of the 

 cliffs mentioned above. This jungle is composed largely of trees 

 of Acacia macracantha, Bursera graveolens, Erythrina velutina, 

 Opuntia myriacantha, and Piscidia Erythrina. The specimens 

 of Opuntia are very large, some of them attaining a height of 

 thirty or more feet. In general it may be said, that nearly all 

 of the species Avhich occur in this area either attain a larger size, 

 or grow more abundantly than they usually do so near to sea 

 level. There is a dense growth of bushes underneath the trees 

 consisting of Cordia lutea, Croton Scouleri varieties, brevifolius 

 and Macraei, Discaria pauciflora, Gossypium barbadense, Lan- 

 tana peduneularis, Maytenus obovata, Parkinsonia aculeata, 

 Prosopis dulcis, Scalesia gummifera, Telanthera echinocephala, 

 Tournefortia pubescens, and Zanthoxylum Fagara. Such ferns 

 as Polypodium squamatum and Trachypteris pinnata grow on 

 the sides of the cliffs at an elevation of 75 ft. Above these cliffs 

 there is a considerable area which is covered with Prosopis and 

 other bushes of an xerophytic character, but the arrangement of 

 these is more open than below the cliffs. The trees of Opuntia 

 myriacantha are numerous and very large in this area, and form 

 a portion of the continuous zone of Opuntia trees which extend 

 around the south side of the island. They are so numerous here 

 that their redish-brown trunks give this color to the surrounding 

 landscape when seen from a distance. 



There is a general thickening up of the vegetation further in- 

 land, but there is not much change in the species of plants pres- 

 ent below 350 ft. Around this elevation such forms as Cordia 

 lutea, Croton Scouleri var. brevifolius, Discaria pauciflora, 

 Opuntia myriacantha, Parkinsonia aculeata, Piscidia Erythrina, 

 Prosopis dulcis, and Telanthera echinocephala disappear. The 

 most of the vegetation, around this elevation, is heavily covered 

 with fruticose lichens. There are dense forests here made up 

 largely of trees of Pisonia floribunda, Scalesia pedunculata, and 



