NATURAL AREAS AND REGIONS 



643 



drier parts. Strophocheilus oblongus is 

 especially characteristic, although it 

 occurs in the heavier forest. Deer 

 (Odocoileus gymnotis and Mazuma nemo- 

 rivaga) are more common in the drier 

 forest and "monte" than elsewhere. 

 This type of forest has suffered most from 

 burning and cultivation. In general, 

 the fauna is quite similar to the rain 

 forest although usually much poorer. 



1. Deciduous thorn forest. The thorn 

 forests, which extend along the coastal 

 belt from the western boundary to the 

 peninsula of Paria, are also represented 

 inland in some parts where they merge 

 little by little into the savannas. 

 Cactaceae, such as Pereskia Guamacho, 

 Lemaireocereus deficiens, L. griseus, 

 Cephalocereus Moritzianus, Acanthocer- 

 eus pentagonus, Opuntia caracasana, 

 0. caribaea and others are typical of 

 this formation, in which grow also 

 several species of Pithecolobium, Bume- 

 lia and Jacquinia, Acacia macracantha, 

 A. tortuosa, Caesalpinia Coriaria, Pro- 

 sopsis juliflora, and other thorny trees 

 and bushes. In the middle of these, 

 larger trees, unarmed, and almost 

 deciduous, appear here and there; they 

 are principally Bursesa Simaruba, Esen- 

 beckia Atata, Aspidosperma Vargasii, A. 

 lucentivenium, Amyris balsamifera and 

 A. simplicifolia. Mention should be 

 made also of the several species of 

 Capparis and Croton. 



With some variations as to its compo- 

 sition, the same formation is spread 

 throughout the interior of the country, 

 where Mimosa Cabrera is one of preva- 

 lent species, along with Caesalpinia 

 Coriaria, and extensive colonies of the 

 palm, Copernicia tectorum, interrupt 

 the low forest here and there. 



The appearance of the thorn forest 

 varies according to the degree of prom- 

 inence of one or the other of the 

 elements of its vegetable covering. In 

 many parts along the coast, on steep 

 hills, and in certain devastated dis- 

 tricts, cacti occupy the space to the 

 almost complete exclusion of other 

 species; in other parts, this formation 

 intergrades into the. next. Between 



these arborescent species, the soil is 

 almost bare or has a spare covering of 

 grasses and other herbaceous or f ruticose 

 plants. The general impression is 

 always one of excessive aridity. 



Fauna (H. B. .). This practically 

 coincides with the thorn formation of 

 Sievers' map. In some places, as 

 indicated above, the prominence of the 

 cacti causes it to assume almost the 

 aspect of a succulent semi-desert. 

 Bulimulus cacticolus is a characteristic 

 snail of these places. A peculiar phase, 

 little studied, occurs on the fossil 

 coral-reefs of some parts of the coast; 

 Sievers includes these, with the usually 

 adjacent sand dunes (Coccoloba uvifera 

 is characteristic) in his "Strand Vege- 

 tation." Most collectors, including my- 

 self, have neglected this type of country 

 for the richer rain forest. It is very 

 probable that the molluscan fauna will 

 be found richer in Antillean elements, 

 like that of the Dutch Leeward Islands, 

 as there are a number of doubtful records 

 of West Indian genera (Eutrochatella, 

 Cerion, etc.) from northern South 

 America. Brachypodella nidicostata has 

 been described from limestone cliffs 

 near Chichiriviche. The rabbit, Sylvi- 

 lagus cumanicus, appears fairly char- 

 acteristic of this type of brushland in 

 eastern Venezuela. 



2. Semi-desert. The semi-desert is 

 simply a transition from the thorn 

 forest to the savanna, and perhaps to 

 the Arid Deciduous Forest. Here, the 

 armed trees are in the minority, and 

 among the unarmed ones, many assume 

 considerable dimensions. On the out- 

 skirts of the savanna, the semi-desert 

 is formed mainly by stunted trees such 

 as Curatella americana, Bowditchia vir- 

 giliodes, Byrsonima crassifolia and B. 

 coccolobaefolia. In other parts, the 

 gregarious Bursera gummifera, with 

 its reddish, constantly peeling trunks, 

 is conspicuous, and Gyrocarpus america- 

 nus grows in places in almost pure 

 stands. Bursera tomentosa, Ruprechtia 

 sp., etc., also occur frequently in this 

 formation, which may pass almost 

 unnoticed by the layman. 



