( 13-'' ) 



and mountain ranges forming the watershed between the basins of the Amazon 

 and Orinoco rivers, marked as the " Sierra Parima" on the maps ; bnt the many 

 difiicnlties mentioned at the beginning of onr article prevented them from doing so. 



Nevertheless the results of their collecting, together with those gained from 

 the collection of liirds made on the Caura River by Mr. E. Andre, are very satis- 

 factory. The number of sijecies contained in the three collections is considerable, 

 and not only are there among them a fair proportion of hitherto nndescribed and rare 

 forms, bnt many others, the occurrence of which it the Orinoco region is of special 

 zoogeosfraphical interest. 



The forms from Ciudad Bolivar' (or Angostura) and Altagracia are those of the 

 Lower Orinoco, more or less well known from the delta of that great river. At 

 Caicara, where the Orinoco, receiving the large Apure river, whose waters drain 

 the Venezuelan Andes, bends its course from a northerly direction in a right 

 angle to the east, and at Ferico and Kaipures, on the upper part of the Orinoco, 

 the proportion of forms princij)ally and often hitherto only known from UjiXJer 

 Amazonia and the eastern Andes is most interesting. 



Ou the other hand, the oruis of the Canra River, a mighty affluent to the 

 Lower Orinoco from the south (birds being received iVoni the places called .Suapure, 

 Temblador, La Pricion, La Union, and the lower jiortion of the Nicare river, a few 

 miles from its junction with the Caura), resembles more closely that of .British 

 Guiana, so well explored by Schomburgk, the late H. Whitely, and others, while 

 quite a number of forms are of other most interesting origin and new to science. 



Unlike the affluents of the left bank, like the Meta and Apure, which flow for 

 their greater part through level prairie country, those on the right, especially the 

 Garoni and Caura, rush through a hilly country of dense forests and numerous 

 isolated mountains and hill-ranges, and their navigation is difficult and dangerous, 

 as illustrated by the mishaps of Mr. Andrii. The lower course of the Caura is 

 known as the princijial district from whence the Tonka bean of commerce, i.e. the 

 dried seed of the fruit of Dipterix odorata, is collected and exported.* 



It will be noticed that, instead of quoting the best-known works, as is 

 frequently done now, such as the Catalogue of Birds and others, where everybody 

 knows that the bird is described or mentioned, and where every one can look up 

 its description without an extra reference to it, we have in every case quoted the 

 original description, which is the basis of onr knowledge of each particular form. 

 We have, however, not merely quoted it, bnt we have looked it up, critically 

 considered its meaning and value, and quoted the first original locality given. 

 Where no locality is .stated in the first description, or where the given locality is 

 vague or erroneous, we have added or substituted a sufficiently exact " habitat " 

 as a starting-point. These additions and sulistitutes are not arliitrarily chosen, bnt 

 always those that are the actual or the most likely ones whence the types have 

 come, as apparent from the history of collections, from the travels of collectors, 

 and the distribution of the various forms. Our substituted localities are therefore 

 not only of value for the present work — inasmuch as they indicate that particular 

 form with which we have compared, or tried to compare, the specimens before ns, 

 when deciding about their subspecitic relations — but we expect them to be accepted 

 as the starting-point for future work also. If new forms of a former customary 



* We learn that a book on the Caura River, its hislory, [irreUicts and nature, by Mr. Andre, illustrated 

 by photographs and maps, is in print ; and we see £rom_some proof-sheets which the author sent to Tring 

 that frequent references to the more conspicuous and important birds are made in (ho work. 



