18. THALTTEANIA. 85 



Specimens from Eritish Guiana also vary in the length and depth 

 of the bifurcation of the tail ; they also vary in the colour of the 

 upper tail-coverts, some being greener, others more bronze ; the 

 same variation is to be found in a scries of Cayenne birds. The 

 under tail-coverts of the British-Guiana birds are, as a rule, steel- 

 blue, like those of T. refulgens, but the character is not quite con- 

 stant, some individuals showing light edges to these feathers. I do 

 not, therefore, see any tangible character by ■which to separate the 

 British-Guiana bird. 



Hab. Guiana. 



a, (5'ad. ; b, c. J Bartica Grove, Brit. Guiana, Salvin-Godman Coll. 



ad. sk. April, June, and Nov. (H. 



Whitely). 

 d. cJad. ;<>. 5 ad. Caniacusa, Brit. Guiana, April Salvin-Godman Coll. 



sk. {H. W.). 



f. (S ad. sk. Mernme Mts., Brit. Guiana, Sclater Coll. 



July (if. \V.). 



(J. (Jad. sk. lioraima, l^rit. Guiana, Nov. Salvin-Godman Coll. 



{H. Whitely). 



h, i. S ad. sk. Demerara. Gould Coll. 



j. (S juv. sk. Cayenne. H. C. Rothery [P.]. 



k-p. c? ad. sk. (Caynene make.) Salvin-Godman & 



Gould Colls. 



g. (S ad. .st. Purchased. 



12. Thalurania furcatoides. 



Thalurania furcatoides, Gould, Mon. Troch. ii. {sub T. furcata, 

 pi. 101) ; id. Intr. Troch. p. 77 ; Muls. o,- Verr. Class. Troch. p. ol ; 

 6W. Sf Salv. F.Z.S. 18G7, p. 584; Snlv. ^ Elliot, Ibis, 1873, 

 p. 357 : Layard, Ibis, 1873, p. 388 ; Muls. Hist. Kat. Ois.-Mouches, 

 iii. p. 73, iv. p. 218 : id. Ann. 8oc. Linn. Lyon, xxii. p. 219 ; Elliot, 

 Syyi. Troch. p. 100 ; Eudes-Desl. Ami. Mus. Caen, i. p. 316. 



Thalurania forcipata, Heine, J. f. Orn. 18G3, p. 181. 



Thalurania subfurcata, Heine, J.f. Orn. 1863, p. 181 ? 



Polytmus furcatoides, Gray, Hand-l. B. i. p. 130. 



Thalurania furcata, Feh. Orn. Bras. p. 30. 



Adult male, Yery similar to that of T. furcata, but with the tail 

 considerably shorter and less deeply forked (central rectrices 0*9 

 inch, lateral 1-4), and with the under tail-coverts white with steel- 

 blue discs. 



T. forcipata is a name substituted by Heine for T. furcatoides, 

 and T. subfurcata is, Count Berlepsch tells me, probably referable 

 to the same species. He also tells me that Natterer s birds from 

 Barra, called by v. Pelzeln T. fiircaia, belong rather to T. fur- 

 catoides. 



Hab. Lower Amazons Valley. 



a-c.c?ad. ; <Z.$ l^wa. {A. B. Wallace?). Gould Coll. 



ad.sk. (Types of the species.) 



e. cJad.:/. $ad. Para, Nov. and Dec. {E. L. Tweeddale Coll. 



sk. Layard). 



g. (S ad. sk. Para i" Gould Coll. 



