vor 

 18»1 



m,""'] PROCEEDINGS OF THE NATIONAL MUSEUM. 533 



logue of Birds ill the British Museum, in treating of the genus Myrmeciza 

 does not mOiWtiow sUctoptera even in his synonymy. 



Picolaptes compressus (Scl.) 



An examination of a seriesof tliirty-three specimens taken from vari- 

 ous points and altitudes on both tlie Atlantic and Pacific sides of the 

 high interior of Costa Rica shows much iudividual variation in size and 

 color; variations that seem to connect (very closely indeed) comprcasus 

 with gracilis. I have not, unfortunately, the type oi^ gracilis before me, 

 but have carefully studied Mr. Kidgway's original description (Proc. 

 U. S. National Museum, Vol. xi, p. 542) aud also Mr. Sclater's notes, 

 taken from the type (Cat. Birds British Museum, xv, p. 154). From the 

 appended table of measurements it will be seen that the variations in 

 size are from: wing, 3.93 to .").4(); tail,3.9(» to 3.43; from nostril to tip of 

 bill, 1 to 0.70; tarsus, 0.71 to 0.05. In arranging the table I separated 

 the birds into four groups; the first from the central west coast region 

 (Gulf de Nicoya). These prove to be slightly the largest and are as 

 a whole a lighter brown (sepia) below; the i)aler markings vary from 

 deep bull to bulfy-whitish, the feathers of the throat usually luirrowly 

 bordered with blackish. Above there is no appreciable difference in 

 color from birds from other localities. 



The second grou^) comes from the east side of the Cordillera, in nearly 

 the same latitude as the first group and at an elevation of about -,500 

 feet. The bill averages slightly smaller and darker horn-color. The 

 coloration above and below is not to be distinguished from that of birds 

 belonging to the first group. It will be noted that the two lots were 

 taken at the same season. 



The third grou^) comes from the southwest coast region. They are 

 intermediate in size, although slight the difference, between the first 

 and second groups; they average slightly darker below, more of a 

 bistre than a sepia brown. The bill is about as dark as in birds of 

 the second group. 



The fourth group is from the eastern side about the same latitude as 

 the last. The birds of this group average decidedly the smallest ; there 

 are, however, only four of them. No. 5437, Museo Nacioual de Costa 

 Kica, is especially small. Above and below the brown is of a darker 

 shade. The ui>per mandible is blackish, the lower horn-color for at 

 least the basal half, the interior half being broken away. 



The birds in the tiiird group, from Pozo Azul, are from the same geo- 

 graphical region as the type of gracilis (Monte liedondo), but certainly 

 can not be seperated from other examples of compressus. I think anyone 

 with my series of birds before them, and with only the descriptions of 

 co))q)ressus and gracilis to guide them, would conclude that the color- 

 differences were very slight, and that the relative measurements were 

 hardly trustworthy characters.* 



The type o( gracilis seems to have an unusually long tarsus. 



Sec these Proceedings, vol. xiv, p. 47.'). 



