238 BIRDS OF LA PLATA 



of the Rio Colorado, It differs externally in the 

 more earthy hue of its plumage, which is protective 

 and harmonises admirably with the colour of its 

 sterile surroundings ; also in having a shorter beak, 

 and in being adorned with a long, slender, black crest, 

 which the bird when excited carries directed for- 

 wards like a horn. There is, however, an anatomical 

 difference which seems to show that the two species 

 are not very near relations* The structure of the 

 intestinal canal in the Martineta is most peculiar, 

 and unlike that of any other bird I have ever dis- 

 sected : the canal divides near the stomach into a 

 pair of great ducts which widen towards the middle 

 and extend almost the entire length of the abdominal 

 cavity, and are set with rows of large membranous 

 claw-shaped protuberances. 



The Martineta inhabits the elevated table-lands, 

 and is found chiefly where patches of scattered dwarf 

 scrub occur among the thorny thickets. Apparently 

 they do not require water, as they are met with in 

 the driest situations where water never collects. 

 They are extremely fond of dusting themselves, and 

 form circular nest-like hollows in the ground for 

 that purpose ; these hollows are deep and neatly 

 made, and are visited every day by the same birds 

 throughout the year. They live in coveys of from 

 half a dozen to twenty or thirty birds, and when 

 disturbed do not as a rule take to flight at once, but 

 jump up one after another and run away with amazing 

 swiftness, uttering as they run shrill, squealing cries, 

 as if in the greatest terror* Their flight, although 



