1873.] CERTAIN MUSCLES OF BIRDS. 641 



Species examined. 



Rallus aquaticus. Ocydromus sylvestris. 



Ar amides cayennensis. Porphyriomadagascariensis. 



Porzana americana. melanotus. 



caro!i?iensis. Gallinula chloropus. 



Crex pratensis. 



The Grallce possess the ambiens, the femoro-caudal, the semiten- 

 dinosus, the accessory semitendinosus, and the postacetahular por- 

 tion of the tensor fasciee ; the accessory femoro-caudal may be pre- 

 sent or absent. 



It is present in : — 



Glareola, sp. Charadrius hiaticula. 



Numenius arquatus. Himantopus nigricollis. 



phceopus. Parra africana. 



Hcematopus niger. 



It is sometimes present (very small), sometimes absent, in : — 

 Charadrius pluvialis. Vanellus cristatus. 



It is absent in : — 



Strepsilas interpres. Scolopax rusticola. 



Limosa rufa. Gallinago scolopacina. 



Totanus calidris. gallinula. 



solitarius. Calidris canutus. 



Gambetta flavipes. Tringa cinclus. 

 Machetes pugnax. 



The Gavice possess the ambiens, the femoro-caudal, the semiten- 

 dinosus, and the accessory semitendinosus ; the postacetahular por- 

 tion of the tensor fasciae is slightly developed in Larus and Lestris, 

 but not in Sterna ; the accessory femoro-caudal is present, though 

 small, in Sterna, but absent in Larus and Lestris. 



Species examined. 



Lestris antarcticus. Larus glaucus. 



Larus argentatus. Sterna hirundo. 



The Procellariidce must be considered under two divisions, the 

 Storm-Petrels and the true Petrels. 



The Storm-Petrels possess the femoro-caudal, the accessory 

 femoro-caudal, the semitendinosus, the accessory semitendinosus, 

 and the postacetahular portion of the tensor fasciae ; the ambiens 

 were present in a black one, but quite absent in three specimens of 

 a light-grey species. 



Species examined. 

 Procellaria pelagica 1 Procellaria fregata 1 



The true Petrels possess the ambiens, the femoro-caudal, the ac- 

 cessory femoro-caudal, and the semitendinosus ; the postacetahular 

 Proc. Zool. Soc— 1873, No. XLI. 41 



