34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



Sida rhotnbifolia. Sagraa petiolata. 



Pachira aquatica. Styrax argenteum. 



Quararibea pterocalyx. Mimusops dariensisr 



Eschweilera panamensis. Malouetia panamensis. 



Eschweilera reversa. Enallagma cucurbitina. 



Gustavia nana. Jacaranda copaia. 



Gustavia parvifolia. Macfadyena uncinata. 



Combretutn coccineum. Aphelandra sinclairiana. 



Cotnbretum epiphyticum. Aphelandra tetragona. 



Combretum punctulatum. Diodia radula. 



Aciotis purpurascens. Cassupa panamensis. 



Clidemia dentata. Macrocnemum glabrescens. 



Clidemia petiolaris. Morinda panamensis. 



Conostegia speciosa. Psychotria magna. 



Conostegia subcrustulata. Rustia ferruginea. 



Leandra cinnamomea. Rustia occidentalis. 



Leandra mexicana. Watsonamra gymnopoda. 



Miconia barbinervis. Watsonamra macrophylla. 



Miconia nervosa. Watsonamra magnifica. 



Oxymeris cinnamomea. Watsonamra pittieri. 



Oxymeris heterobasis. Watsonamra pubescens. 



ARID LOWER TROPICAL ZONE 



The Arid Lower Tropical Zone extends in a belt of varying width, 

 mainly at low elevations, all along the southern side of the Isthmus, 

 excepting possibly the extreme southeastern part, from the Pacific 

 coast line to near the base of the higher mountains, reaching farthest 

 inland along the valley of the Tuyra River and at the base of the 

 Azuero Peninsula. In the vicinity of the Canal Zone it crosses the 

 continental divide and invades a part of the valley of the Chagres 

 River ; important islands off the coast are also included in its scope. 



The total rainfall is by no means scanty, and in the wet season the 

 forested parts of this zone differ little in appearance from Humid 

 Lower Tropical areas, truly arid conditions prevailing only during 

 the dry season when much of the forest, except near water, is leafless 

 and the contrast with the continuously humid areas is very striking. 

 A number of trees exhibit the strange habit of devoting the wet 

 season to purely vegetative functions; under the stimulation of the 

 first rains newly formed leaves and rapidly lengthening branches 

 give the forest a spring-like appearance, but the flowering and 

 maturing of fruit is deferred until the dry season, when the leaves 

 have fallen and general growth has stopped. 



Mammals of Arid Lower Tropical Zone 



Didelphis marsupialis particeps, San Miguel Philander laniger palliHus, Pale Woolly 



Island Opossum (San Miguel Island). Opossum. 



Didelphis marsupialis battyi, Batty's Opos- Philander laniger nauticus, Insular Woolly 



sum (Coiba Island). Opossum. 



Marmosa mexicana savannarum, Savanna Odocoileus chiriquensis, Chiriqui White- 



Marmosa. tailed Deer. 



Marmosa fulviventer, Fulvous-bellied Mar- Odocoileus rothschildi, Rothschild's White- 



mosa (San Miguel Island). tailed Deer (Coiba Island). 



