the rapid deterioration of Bullet^vood in these tests and of Ljcaria csnolla 

 ill tests conducted by Edraondson in Hawaii, 



A niffliber of woods listed in Table 2 for which exposure data are not yet 

 available would appear on the basis of their silica content to be highly 

 resistant to attack, /anong such woods ax'e Licunia buxifolia, Parinari 

 excelsa, Licania macrophylla, Eschweilera odora, FaFinari Kodolphi , i-'arinari 

 campestri s, and Bs chweilor"a~subgTa"ndulo sa . 



The folloYtting paragraphs briefly describe the species that have shovm best 

 performance to date in these marine borer exposure tests. These species 

 are arranged in approximate order of indicated resistance. Vi/hile shov;ing 

 good resistance to marine borers, several of these species are not out- 

 standing in their resistance to decay, suggesting the possibility that longer 

 service life may be obtainable from, them if they were given a preservative 

 treatment to improve their performance in this respect, 



1. Acapu ( Vouacapoua american a) . See description under Species Suitable 

 for Above-Vifater Construction, 



2. ilorrao (Eschweilera blanchetiana ) . This is one of about 80 species of 

 medium-sized to very large trees of the genus Eschvireilera occurring from 

 eastern Braail through the Amazon basin to Trinidad and Costa Rica. Little 

 specific information is available concerning the abundance or distribution 



of Morrao, but the material used in these tests originated near Belem, Brazil. 

 The wood appears to share the general characteristics of the ilanbarklak group 

 of Eschweilera . These timbers "are extremely hard and strong with air-dry 

 weights of 69-78 pounds per cubic foot. Ilie vraod is difficult to work and 

 highly durable with respect to decay and, as noted previously in this paper, 

 with an outstanding reputation for marine borer resistance. Record and Hess 

 (6) report that the only dama-e to Manbarklak after years of service in 

 brackish waters infested by Neoteredo was a slight superficial injury in- 

 flicted by the marine stone borer, xiartesia cuneiformis . 



3. Sapucaia ( Lecythis usitata ) , The genus Lecythis includes a large number 

 of imperfectly Imown species which are widely distributed from southeastern 

 Brazil through northern ^outh America to Costa Rica. The name Sapucaia is 

 applied to most of the Brazilian species of Lecythis . These trees are com- 

 mon in both the Amazon lowlands and the coastal mountains. The trees are 

 large, often reaching 5-6 feet in diameter with buttressed boles extending 

 free of branches for 50-60 feet. 



The wood of Sapucaia is typically veiy hard, strong, and heavy, weighing 

 from 53-69 pounds per cubic foot when air dry. The tmbers of this group 

 vary from fair to excellent in decay resistance. They are used m heavy 

 construction, in bridges, and as railway crossties in Brazil, 



h. Angelique ( Dicorynia paraensis ). This tree is abundant ±ci Surinam, 

 French Guiana, and the Brazilian Jimazon. It is reported to be one of ^the 

 most commn of the larger trees along the Rio Negro. The tree of Angelique 

 is large, attaining diameters of 5 feet or more and heights up to 150 feet. 



T - 10 



