612 Bulletin of the British 



exhibited some interesting specimens of the eggs of Larus 

 canus ; also the photographs he had taken of the different 

 islands and the nests of the birds found tlicreon. 



Mr. W. P. Pycraft made a communication concerning the 

 avian " mesopterygoid " of W. K. Parker. This, he showed, 

 did not represent a mesopterygoid, but was really a segmen- 

 tation of the anterior end of the pterygoid, which, running 

 forward along the internal border of the posterior end of 

 the palatine, terminates over the posterior extremity of the 

 vomer, with which it is often in actual contact. This is the 

 permanent condition of these bones in the Ratitae, where, 

 however, the anterior end of the pterygoid does not segment 

 off from the main body of the bone. In the Ca7nnat(E, later 

 in life the segmented anterior end fuses with the palatine 

 and thus disappears, a true joint being formed behind this, 

 the pterygo-palatine articulation. Thus, the pterygoid of 

 adult modern Carinatce represents only the posterior portion 

 of that bone, the anterior portion having fused with the 

 palatine. The matter will be dealt with fully in a forth- 

 coming paper. 



Mr. C. F. Underwood described four apparently new 

 species of birds from Costa Rica and Guatemala : — 



TiNAMUS SALVINI, Sp. U. 



7'. similis T. jvscipenni, sed mnlto miner, et secundariis 

 extiis pallide rufo fasciatim notatis : praepectore et 

 pectore summo olivascenti-griseis, fulvo transfasciatis : 

 abdomine albicanti-fulvo, distincte nigro transfasciato. 

 Long. tot. 105 poll., culm. 115, alee 7'2, caudse 2*0, 

 tarsi 20. 

 Hab. Carrillo, Costa Rica, Nov. 30, 1897 (C. F. U.). 



Chlorospingus olivaceiceps, sp. n. 

 C. similis C. canigulari, Lafr., sed pileo olivaceo dorso con- 

 colore distinguendus. Long. tot. 5'0 poll., culm. 0'45, 

 alse 2'6, caudse 2*05, tarsi 0'75. 

 Hab. Carrillo, Costa Rica, Nov. 24, 1897 (C. F. U.). 



Icterus gualanensis, sp. n. 

 Similis /. giraudi, sed capitis nigredine usque ad occiput 



