254 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Immature: Similar, but pileum and auriculars plain brownish-black; 

 chin and throat more heavily marked (squamated) with dusky, and sides 

 brighter rufous. Superciliary streak obsolete, except above the auricu- 

 lars. 



Hab. — La Palma and Navarro, Costa Bica (altitude about 3,500-5,000 

 feet). 



The most striking characters of the two known species of this genus 

 may be contrasted as follows : — 



P. boissoneauti. — Tufts on side of neck pure white. Primaries and wing-coverts fer- 

 rugineous-umber. Jugulum faintly squamated with dusky. Hab. — New Granada 

 and Ecuador. 



P. laivrencii. — Tufts on side of neck creamy-buff. Primaries and wing-coverts brown- 

 ish-black. Jugulum heavily striped with dusky. Hab. — Costa Eica. 



The proportions of both species are exceedingly variable, as may be 

 seen from the accompanying table of measurements, and are therefore 

 of no use as specific characters. 



The new form (P. lawrencii) was also obtained by Mr. A. Boucard at 

 Navarro, Costa Eica, but that gentleman evidently overlooked the more 

 important differences of plumage, though he alludes to the different color 

 of the neck-tufts (Proc. Zool. Soc. Lond. 1878, p. 59), adding that he does 

 not u for the present consider this difference sufficient to make another 

 species of it v . 



Following is a more detailed description of P. boissoneauti, and tables 

 of measurements of both species. 



PSEUDOCOLAPTES BOISSONEAUTI, Lafr. 



Sp. CH.— Wing, 3.85-4.65 ; tail, 3.70-4.60 ; bill, from nostril, .42-.70; 

 tarsus, .95-1.10 ; middle toe, .58-.70. Primaries and wing-coverts umber- 

 brown, like the tertials; primary-coverts, dusky. Tufts on sides of 

 neck pure white. 



Adult: Pileum, auriculars, nape, and anterior portion of back brown- 

 ish-black,- streaked with pale fulvous, these streaks much broader, 

 and very conspicuous, on the nape and back. Lower part of back, 

 scapulars, and wings ferruginous-umber, the middle and greater coverts 

 tipped with fulvous. Bump, upper tail-coverts, and tail deep brick- 

 rufous, immaculate. A narrow superciliary streak of pale buff. Chin 

 and throat white ; neck-tufts pure silky white. Jugulum and breast 

 buffy white, or very pale buff, faintly squamated with dusky, these 

 markings heavier on sides of the breast. Best of lower parts plain 

 ochraceous-rufous, slightly paler on the middle of the abdomen. Bill 

 black; lower half of mandible whitish. 



Young: Pileum and auriculars plain brownish-black; superciliary 

 stripe obsolete, except above the auriculars. Bill wholly black, but 

 somewhat paler on gonys. 



