440 Zoological Society : — 



racescenti-alba, abdomine fiavido lavato : rostro superiore ob- 

 scure corneo, inferiore rubello : pedibus nigris. 



Long. tota. alae. caudae. 



Spec, a, rf, 5-4 3-0 27 



b, $, 5-0 27 2-2 



c, ? 6-0 3-1 2-8 



d, 60 2-9 27 



e, 57 2-8 25 



/, 5-8 3-0 2-8 



g, 5-8 3-0 2-8 



Hab. In ins. S. Thomse Antillensium. 



Mus. P. L. S. 



Obs. Affinis Elainece pagance et ejusdem formse, sed rostro lon- 

 giore, compression, et corpore subtus pallidiore distinguenda. 



I have specimens of two species of this genus of Tyrannidce in my 

 collection from Jamaica. One of them is E. Cottce of Gosse ; the 

 other, as far as I know, undescribed, but quite different from the 

 present. I have also an Elainea from Tobago, which I cannot refer 

 strictly to any known species. 



On the African Trionyces with hidden feet (Emyda). 

 By Dr. J. E. Gray, F.R.S., V.P.Z.S. 



Five species of my genus Emyda (which MM. Dumeril and Bibron 

 afterwards most unnecessarily named Cryptopus) have been described 

 as found in Africa, viz. — 



1. Cryptopus senegalensis, Dum. & Bib., from Senegal. 



2. Cyclanosteus Petersii, Gray, from the Gambia. 



3. Cyclanosteus frenatus, Peters, MSS., from Mozambique. 



4. Cryptopus Aubryi, Dumeril, from Gaboou. 



5. Aspidochelys Livingstonii, Gray, from Mozambique. 



Now it is very doubtful if several of these names are not synony- 

 mous, not because there is any doubt as to the distinctness of 

 species, as some neophyte belonging to the Darwinian School might 

 suspect, but simply because the materials on which they are founded 

 do not afford us sufficient information or means of comparison. 



Cryptopus senegalensis was described from a very young specimen 

 in the Paris Museum before it had any of the sternal callosities de- 

 veloped. The specimen of Trionyx, with flaps over its feet, which 

 we have received from the same locality, is unfortunately in the same 

 condition ; and though it affords very good evidence that it is desti- 

 tute of any bones on the margin of the shield, and therefore does not 

 belong to the same genus as the Asiatic animal with which M. Du- 

 meril associated it, yet it does not give us the means of knowing to 

 which, if to either, of the two African forms, viz. Cyclanosteus and 

 Aspidochelys, it should be referred. 



The description of Dumeril, and the colouring of the head, &c. of 

 the specimen in the Museum, show that it must be distinct from 

 Cyclanosteus frenatus and from Cryptopus Aubryi (which may be 



