712 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



the National Museum collection said to have been taken on the " Pacific 

 coast of Central America" — a locality too indefinite to be considered 

 in a case of this kind. Both the Bogota black-capped form {P. nigri- 

 ceps anteocularis Hellmayr) and the Venezuelan form (P. plumhlceps 

 Lawrence) have by the latest authority on the genus « been synonymized 

 with P. nigriceps; but I am prepared to prove that, at least so far as 

 the latter is concerned, this is an error. Comparison of an ample series 

 of adult females of P. plumbieeps with an equally good one of the 

 same sex of P. nigriceps shows that the two forms are very distinct, 

 the female of P. plumhicejys having invariably the conspicuous dusky 

 (sometimes nearly black) postocular patch of P. leucogastra, a charac- 

 ter never seen in P. nigriceps. Of P. anteocularis I have not been able 

 to see a female; but I feel reasonably sure that its affinities will also 

 be found to be with P. leucogastra rather than with P. nigriceps. 



P. nigriceps is of very uniform character throughout its range, 

 which extends from southern Sonora to Oaxaca, in western Mexico; 

 but from Oaxaca and Yucatan southward to the Isthmus of Panama 

 all the forms of this genus are involved in much uncertainty. P. albi- 

 ventris is apparently confined to Yucatan; this is, normally, a form 

 without any white on lores or about the eye, in this respect agreeing 

 with P. nigriceps; but some specimens show more or less of white on 

 the lores and behind or above the eye, thus suggesting intergradation 

 or hybridization with P. albiloris or P. superciliaris, both of which 

 occur in the adjacent territory of Guatemala. Under the names of 

 P. albiloris and P. iilineata, two quite easily recognized forms have 

 in each case been included; under that of P. nlliloris a smaller and 

 shorter- tailed form, halving a black line across the white lores, occur- 

 ring ill western Nicaragua and Costa Rica; and under that of P. lilin- 

 eata, (1) a form resembling the last mentioned in coloration, except 

 that it has no black line on the white lores, and with a distinct white 

 superciliary stripe, besides having the tail still shorter, and (2) a 

 smaller, much shorter tailed, darker colored bird having the same 

 pattern of head markings. The last mentioned, which is P. sujx'r- 

 ciliaris Lawrence, extends, apparently without variation, from the 

 Panama Railroad to Guatemala; the other, which is probably P. hilin- 

 eata (Bonaparte), extends from Chiriqui to the province of Santa 

 Marta, Colombia, thus overlapping for a short distance the range of 

 P. superciliaris., within which occur two othej- forms — P. aXbilcn'is in 

 Guatemala and P. hairdi in western Nicaragua and Costa Rica. 



It will thus be seen that the case is much complicated, and that it 

 would not be advisable in the present state of our knowledge to attempt 

 to distinguish certain of these forms as subspecies rather than species, 

 but much better to leave the final adjustment of their relationships to 

 some one who may be able to examine a satisfactor}^ amount of material. 



o Hellmayr, in Tierreich, 18 Lief., 1903, 25, 26. 



