322 Mr. J. Gould on two new Species of Hummmg-Mrds. 



forms the second head of the fourth dorsal, while the fibular 

 constitutes the abductor minimi digiti. 



Thus we find that all the muscles of the manus and pes may- 

 be reduced into a regular ordinal series. The only supple- 

 mental muscles to these are the lateralizers of the metacarpals, 

 of which two are usually present : — one an opponens of the 

 metacarpal of the thumb, often present as an accidental variety 

 in the pes ; and secondly the lateralizer of the fifth metatarsal 

 bone, present in the foot as the " abductor ossis metacarjji 

 quinti " muscle of Wood, Huxley, and Flower. Perhaps there 

 may be a complete series of these in a typical limb ; but I am 

 not aware of any others being present in any individual animal. 



XL. — Desai'{j)t{ons of two New Species of Humming-hirds. 

 By John Gould, Esq., F.R.S. 



Eriocnemis smaragdim'pectus. 



Head and upper surface dullish grass-green ; rump and upper 

 tail-coverts resplendently luminous yellowish green ; on 

 the throat a patch of violet-blue ; thence to the vent glittering 

 grass-green ; under tail-coverts bright blue ; thighs thickly 

 clothed with white downy feathers ; bill, primaries, and tail- 

 feathers black. 



Total length 4 inches, bill |f , wing 2^, tail If. 



Hab. Ecuador. 



Remark. — This species, which is from the neighbourhood 

 of Quito, is very closely allied to Eriocnemis vestita, but differs 

 from that bird in the green of the breast commencing imme- 

 diately below the blue throat-spot, whereas in fine old males 

 of E. vestita, when viewed in bright sunlight, a black band 

 is seen separating the two colours. It is true that this band 

 is green in certain lights ; but the feathers are of a different 

 structure to those of the Quitan species. Taking the average 

 of seven specimens of both kinds, I find the E. smaragdinipectus 

 has a rather longer bill and somewhat shorter wing than the E. 

 vestita ; in all other respects their dimensions are very similar. 

 The green of the abdomen of the former is more pure, or not 

 so yellow as the same part of the latter ; in the gorgeous 

 colouring of the rump perhaps the Quitan bird is somewhat 

 less resplendent than the Bogotan E. vestita. I have ample 

 materials at my disposal for determining the distinctness of 

 the two birds ; and, however similar they may be, there are 

 sufficient tangible characters by which each may be recog- 

 nized, and to show that they are really different. 



