62 MR. A. BOUCARD ON BIRDS FROM COSTA RICA. [Jan. 15, 



Subfamily Formicariin^e. 



187. Pithys bicolor, Lawr. 



One specimen, from San Carlos, February. 



188. FORMICARIUS HOFFMANNI, Cab. 



One specimen, from San Carlos, February, killed in the forest, 

 on the ground. This bird is constantly going about, and has a 

 peculiar way of raising and lowering its tail when running along, 

 with which I was very much amused. I saw several other speci- 

 mens always on the ground- The same thing occurs with the birds 

 of the genus Siurus. 



189. Grallaria perspicillata, Lawr. 



One specimen, from San Carlos, February. Very rare. 



Family Tyrannid^e. 



190. Sayornis aouatica, Sclat. & Salv. 



Several specimens, from San Jose, January, March. This bird has 

 the curious habit of staying all day long on the stones or bushes grow- 

 ing in or near the streams. It will always be seen at the same 

 place for hours and days one after another. It lives on all the 

 insects flying about over the stream. They are always seen in pairs, 

 d and $ . Another pair may occasionally be seen at a short 

 distance. 



Subfamily Platyrhynchin^e. 



191. Platyrhynchtjs albigularis, Sclat. 

 One specimen, from Navarro, May. 



192. TODIROSTRUM CINEREUM, L. 



Several specimens, from Cartago and San Jose. Rather rare. 



193. Euscarthmus sauAMiCRiSTATUs, Lafr. 



Two specimens, from Naranjo, April. A rare species and difficult 

 to detect. Goes about in the forest on the small trees. 



194. Serpophaga cinerea, Strickl. 



FromNaranjo, April. Excessively rare and remarkable for its habits. 

 It has exactly the same mode of life as Sayornis aquatica, living 

 along the streams and sitting on the stones lying in or near the 

 water. 



First I killed the $ , in the morning, and for hours could not get 

 a shot at the c? , and went away. In the afternoon I went again 

 to the same place, and after a little while managed to kill the <S 

 bird. The two sexes are exactly alike. 



My specimens differing from the Columbian bird, which I have 

 under the name of S. cinerea, I give a description of them : — 



Forehead and cheeks quite black, with the inner webs of the 

 central feathers white, back and upper coverts of the tail ashy grey ; 



