446 



RlAMA UNICOLOR. (PI. XV. fig. 2.) 



Uniform lead- coloured in spirits ; tail longer than the body and 

 head, tapering to a fine point. 



Hah. Ecuador (Mr. Louis Fraser). 



Length : body and head 2\, tail 3^ inches. 



It may be observed, that though the genera of the family Chal- 

 cidce all agree in the form and situation of the nostrils between the 

 nasal and labial shields, and in the absence of the external ear, they 

 present two very distinct forms of scaling, forming at least two 

 tribes. Thus : — 



1 . The scales elongate, subquadrate, pointed behind ; the scales 

 in the rings alternating with each other, the points of the scales of 

 one ring being opposite to the suture between the scales in the next 

 ring. — Brachypodina : Br achy pus. 



2. The scales elongate, subquadrate, truncated at the end ; the 

 scales of the different rings opposite each other, forming longitudinal 

 as well as transverse lines. The ventral and subcaudal shields broader 

 than the rest. — Chalcidina : Chalcis — the first having the shield like 

 Chirocolidce and Anadiadce, and the second like Cercosauridee and 

 the genus Riama here described. 



Another genus of this family named Baekia, which is not in the 

 British Museum, is described as having narrow, smooth, six-sided 

 shields on the back, in nineteen longitudinal series. 



EXPLANATION OF PLATE XV. 



Fig. 1. Argalia olivacea, P. Z. S. 1847, p. 97. From Venezuela. 

 Fig. 2. Riama unicolor. 

 All natural size. 



November 9, 1858. 

 Dr. Gray, F.R.S.,V.P., in the Chair. 

 The following papers were read : — 



1. Characters of Five New Species of American Birds. 

 By Philip Lutley Sclater, M.A. 



1. EuCHLORNIS FRONTALIS, sp. nOV. 



Psittaceo-viridis, fronte et gutture flavis ; alls caudaque intus 

 nigris, extus viridi limbatis ; secundariis albo anguste termina- 



