N.VV. Argentina and the Bolivian Chaco. 449 



19. ClILOROSTILBON AUREIVENTRIS (d'Ol'b. et Lafl\) . 



Mr. von Hofsten twice found nests of this little Humming- 

 bird. They are very simply made of grass-straws and wool 

 of the vicuna. In the first was found one, in the other two 

 white eggs measuring 16 by 10 mm. The nests were placed 

 in crevices in the rocks, at steep and inaccessible places. 



20. COLAPTES RUPICOLA d'Ol'b. 



This Woodpecker occurred at an altitude of 5000 metres 

 above the sea-level, but was rather rare. A male and female 

 Avere killed, December 1st, 1901. Dr. Sclater has recorded 

 it as occurring in Peru at an altitude of 12,170 feet 

 (P. Z. S. 1881, p. 488), on the authority of Prof. Nation. 

 It feeds on larva? which it hacks up directly from the 

 ground. 



21. Cinclodes bifasciatus Sclater. 



This bird reminds one in its habits of the European 

 Cinches. It lives on rivulets, hopping from stone to stone. 

 Now and then it dips its head under the water to catch larvae 

 and small crabs, sometimes even descending wholly into the 

 stream. ' It builds its nest of grass-straws in shrubs at the 

 water's edge. It is found up to an altitude of about 5000 

 metres above the sea- level. 



22. Geositta cunicularia (Vieill.) . 



Iris yellowish brown. To judge from the general colora- 

 tion of the plumage and the measurements, the Geositta 

 obtained at Moreno belongs to this species, but the breast 

 seems to be entirely unspotted in the specimens brought 

 home. It may, therefore, perhaps represent a distinct race 

 or subspecies. It is too small to belong to G. rufipennis, 

 from which it also differs in having the second primary 

 almost wholly rufous on the inner web, and the first basally 

 and centrally with a rufous tinge. 



The collector states that this bird is common at Moreno, 

 where it runs on the sandy ground among the Tola-bushes, 

 Heeding on insects. Its flight is in curves up and down, and 

 when it descends it seems to fall vertically to the ground. 



