216 Bulletin American Museum of Natural History. [Vol. XXXVI, 



due to immaturity, and indicate, in my opinion, that venezuelensis (which 

 was apparently based on one specimen) is not a vaUd form. 



Specimens from Andalucia show no approach to bourcieri of which we 

 have skins from La Candela on the opposite side of the Magdalena Valley. 



Puerto Valdivia, 1; Andalucia (5000-7000 ft.), 3; Fusugasuga, 1; 

 Buena Vista, 3. 



Order OPISTHOCOMIFORMES. 

 Family OPISTHOCOMIDiE. Hoatzins. 



(212) Opisthocomus hoazin {Milll.). 

 Phasianus hoazin MtjLL., Syst. Nat. Suppl., 1776, p. 125 (Cayenne). 



Specimens from Florencia and Villavicencio mark the extreme north- 

 western limit of the range of this species. 



Florencia, 6; Villavicencio, 3; Barrigon, 1. 



Order RALLIFORMES. 



Family RALLID^. Rails, Gallinules, Coots. 



(217) Rallus semiplumbeus Scl. 

 Rallus semiplumbeus Scl., P. Z. S., 1856, p. 31 (Bogotd). 



Locally distributed and not uncommon on the Bogota Savanna. 

 Savanna at Bogota, 4. 



(224) Pardirallus nigricans nigricans ( Vieill.). 



Rallus nigricans Vieill., Nouv. Diet. d'Hist. Nat., XXVIII, 1819, p. 560 (Para- 

 guay); Scl. & Salv., P. Z. S., 1879, p. 545 (Medellin). 



Found by us only in the Cauca Valley. Four specimens are all much 

 more olive above and more plumbeous below than a single specimen from 

 "Brazil." 



La Manuelita, 2; Rio Frio, 2. 



