Vol. XLVIII] 1•1 J PE•RS, T/• Yd/ow-•e• 575

AN ACCOUNT OF THE YELIDW-GREEN VIREO (VIREOSYLVA FLAVOVIRIDIS CASSIN)

BY JAMES L. PETE•

Tav• Yellow-greenVireo enjoysa placein the Check-listof the AmericanOrnithologists' Union on the basisof three instancesof accidentaloccurrence within the limits coveredby the Cheek-list. To the bulk of ornithologistsand bird-studentsin this country this bird is a name only, and for that reasonan accountof its history,range, geographic variation, migrations, etc. may proveof some interest. This studyis basedon the seriesof sixty-fiveskins of the species in the Museumof ComparativeZoology, supplemented by over fifty from the main collectionand •ffty-three from the Dwight Collectionof the AmericanMuseum of Natural History. In addition I have examinedsingle birds or small seriesfrom the collectionsof the BiologicalSurvey, Academy of Natural Sciences of Philadelphiaand Mr. DonaldR. Dickey.' It is now generallyconceded that the Yellow-greenVireo is divisibleinto threesubspecies as follows: Vireo fla,•oiridis z/r/d/s(Cassin), Vireo fia,•oiri dis forred Madar/sz, and Vireo fiavoviridisinsulanus Bangs. The speciesbelongs to that groupof moreor lessclosely related Vireosincluding Vireo mag'•terand subspecies,from the islands off the coastof Yucatanand in the Gulf of Honduras;V. caymanen- s/a fromthe islandof GrandCayman; V. olivaeeusand subspecies (Black-whiskeredVireo) of the'West Indies,Vireo olivaeeus • (Red- eyedVireo) from North America,and Vireochizi 2 and subspecies from South America. Of this groupit is most nearly related to Vireooli•meeus, apparently representing it in Mexicoand Central Americaas doesVireo ealidrist in the West Indies, but the dif- ferencesseparating the three groupsare certainlyof more than subspecificvalue.

• While these are the names adopted in the A. O. U. Check-list the author con- siders that oltvaceus?.inn. is based on the West Indies bird and replaces caltdrts which would require the use of v•rescensVieillot for the Red-eyed Vireo. ' • l•r. Todd's paper (Auk, July 1931) appearedlong after the present paper was submitted.--Ed. 576 TheYellow-green Vireo. [Oct.Auk

Vireo fiavoviridis (CAss•N) Description.--Pileum and hind neck mouse gray or neutral gray the anterior part with a dusky border, more or less distinct; superciliary stripe grayish-white; rest of upper parts and tail olive green; wings dusky, the feathers margined with yellowish olive; lores grayish-white like the superciliary, becoming dusky in front of the eye. Below white, flanks and sidesof neck and chest olive yellow, becominglemon yellow on the under tail coverts;under wing covertspale lemonyellow or sulphur yellow. Bill, legsand feet bluish gray or grayish blue in life; iris "red." Wing (males) 74.5-86.5; females 71-78.5. Breeding Range.--Mexico from Sonora and Tamaulipas south to the Canal Zone and the Pearl Islands but absent from the Caribbean coast of south of Guatemala; Tres Mafias Islands.

Vireo fiavoviridis fiavoviridis (CAss•N) Vireosylvafiavovi•idis Cassin, Proc. Ac. Nat. Sci. Phila., 5, 1851,p. 152, pl. 11 ( and ). SubspecificCharacters.--Superciliary stripe distinct, dusky border of pileumusually well defined; sizemedium. Wing (males)77-83; average of 39 breedingbirds 78.2 mm•; females73-80, averageof 14 breedingbirds 76.5. Range.--Mexico from Sonora, Nuevo Leon and Tamaulipas south on the Pacific coast to northwesternCosta Pica and on the Caribbean slope to eastern Guatemala. Apparently absent from the Caribbean rain forest from Honduras southward except that summer birds from eastern Costa Pica (Carillo, 1500 feet and Mojon, 3500 feet) are referableto fixis form. Winters in upper Amazonia. Accidental at Godbout, Quebec (Merriam, 1883), Brownsville,Texas (Merrill, 1878, p. 125) and Riverside, California (Price, 1888). Cassinbased his original descriptionon four specimensin the Academyof Natural Sciences,of Philadelphiabut thesecotypes no longer exist (Stone, 1899, p. 31). His descriptionapplies equallyto f. flavoriridisor f. insulanus,but the wing measurement of 3.2 inchesis equivalentto 81.5 mm. and can apply only to the form breedingin Mexico and northern Central America. Mostpersons who have studied the birds of CentralAmerica in recent years axe now convincedthat the Yellow-greenVireo is migratory,but praetieallynothing has been publishedconcerning the datesof migrationor the winter homeof the species. Cherrie (1890,p. 329) appearsto have beenthe first to recognizethe fact that the bird is not a permanentresident in , stating that it disappearedfrom the neighborhoodof San Jos• with the ¾ol. 1931XL¾III1 J P•a'•as,'TheYe2•ov•r• Vireo. 577 beginningof thedry season at theend of Septemberand reappeared againin April. Alsoas far backas 1881 Salvin and Godman (1881, p. 190)suggested that thebirds taken in winterin SouthAmerica werethere only at that season,this observationbeing prompted by a specimentaken at Yquitos,Peru by Whitelyon 16 October, 1878,together with the lackof recordsof its occurrencein Mexico and Central Americaoutside of the periodfrom April to August inclusive. That the winterhome of the speciesis in AmazonianColombia, Ecuador,Peru and Bolivia, is, I think well established.Early referencesin literature of its occurrencein South America for the mostpart fail to givethe dateswhen the specimenswere secured. The firstpublished instance of its occurrencein Amazoniawas by Taczanowski(1874, p. 509) who recordsa specimencollected at Monterico,Peru by Jelski;the sameauthor (1882,p. 7).lists an exampletaken by Stolzmann23 February1881 at Yurimaguas, Peru. Gadow(1883, p. 295) listssldn.• in the BritishMuseum col- lectiontaken at Guayango,Peru; Rio Nape, Ecuador; and" Bolivia." Todd (1922,p. 434) in detailingthe recordsof V. fia•oviridis fromthe SantaMarta region,shows that all the datesof occurrence thereare between12 Augustand 20 October,when the birdsare cormnonthroughout the lowlandsbelow 1000feet, especiallyin that part of the regionlying westwardof the mountains.The fact that there are no winter or springrecords may indicatethat the bird passesfurther south and possiblyreturns northward by another route. Chapman(1917, p. 539)gives only two recordsfrom , both from Chicoralin the MagdalenaValley, 23 Augustand 13 October. For EcuadorChapman (1026, p. 586) recordsVireo fia•o•iridisfrom SanJose 11 March-ll April andfrom Rio $uno, 7 and 8 March; bothlocalities situated on affluents'ofthe Rio Napo. Besidesthis publishedevidence I haveexamined specimens in the AmericanMuseum of Natural Historyand the Museumof Com- parativeZoology as follows:--EasteruEcuador, Rio Curarayand LagartoCocha 8, 10 Novemberand 18 January. Southeastern Peru: 15, 22 October;10, 13 December;2 February. Bolivia: 23 February,5 March. M•n6gaux(1911, p. A 70) recordsa speci- menof Vireofia,•nriridis from Santo Domingo, Ecuador, a locality 578 [PETERS,TheYellow-green Vireo. [oct.[Auk in the humid tropicalzone of the Pacificslope. I have doubts however as to the eorreetuessof the identification, the bird is givenas a c• with a wingof only 68 mm. and a bill of 12 mm., the wing is muchtoo smalleven for V. f. insulanus,but corresponds with the smallerbirds of the Vireoehivi group. At this point it is importantto rememberthat there is not a singlerecord for any form of Vireofiavoviridis in Mexico or Cen- tral Americabetween 7 Octoberand 14 February. Northward Migration.--As will be shown later, V. f. insulanus arrivesin the Canal Zone aheadof V. f. fiavoviridisso the datesof arrival of one race or the other must rest upon actual specimens. V. f. fiavoviridisputs in its appearancein Panamaat the end of Februaryor the first week in March. Februaryarrivals are most unusual,the only certaindate beingfor a male taken in Chiriqui, 4800 feet, 26 February, 1901 by W. W. Brown; the samecollector alsosecured two femalesat the sameplace 3 and 4 March 1901;a specimenin the BiologicalSurvey collectionwas shot at Taber- nilla, Canal Zone, by E. A. Goldman,12 March 1911. In 1904 when Brown was collectingon SabogaIsland, one of the Pearl Islands,he shotsix malesand two femalesbetween 2 and 12 April, all referableto f. fiavoviridisand did not get the residentinsulanus at all. Evidently the springmigration was then at its height. In the vicinity of San Jos•, Costa Riea, Cherriesays that the bird has returnedto its usual hauntsby the tenth of April. On the Pacificslope of Nicaraguathe earliestdate is 9 April, a speci- men taken by Miller and Griseomin 1917. The earliest date for anywherein Central Americanorth of Panama is that of a specimencollected at Mazatenango,western Guatemalaby Ned Dearborn between 15 and 21 March, 1906 (Dearborn,1907, p. 124); A. W. Anthony shot two malesat La Perla, easternGuatemala 1 and 2 April 1927. On 28 March 1912, I k/lied a singingc• at Camp Mengel, QuintanaRoo. Cole (1906, p. 136)took a maleat ChichenItza, Yucatan3 April 1904. From Vera Cruz there is a male in the M. C. Z. taken at Presidio 6 April 1925,by W. W. Brownand from Oaxaea,a male taken by the samecollector 15 April 1927. As is to be expectedthe first arrival in every easewas a male. On the other hand,a belated migrant from Darien, a female,was taken on Mt. Sapoat Cana, 26 April 1928by R. R. Benson. Vol. 101)1XI•VIIIl J P•,•as,ivh• Yellow• Vir•o. 579

$tmg.--Thesong of the Yellow-greenVireo is practicallyin- distinguishablefrom that of the Red-eye. In CentralAmerica the birdsusually frequent tall treesin the river valleys,but are never foundin the rain forestregions, except when it seemsto be oneof thespecies that worksin if the forestis clearedaway. Nesti•g.--¾erylittle is knownabout the breedinghabits of this bird or eitherof its subspecies,beyond Cherrle's (1890, p. 329-331) account. He first notedbirds near San Jos6,Costa Rica, carryifig nestingmaterial 24 April 1889,and discovereda nestwith 2 fresh eggs12 May; a secondnest conts.lnlng three fresh eggs was taken 21 May and a third nestwith threeheavily incubated eggs 26 May. Thesenests were all suspendedbetween small twigs hanging either abovea streamor low groundat a heightof fromfour to ten feet, and werecomposed of a liningof very fine dry grass,the outside coveredwith softdry leaves,and shredsof paperybark all bound in placewith spiderwebs. The eggsare describedby Cherrieas being"white, speckledchiefly at the largerend with spotsvarying in colorfrom a dark chestnutto an orangerufous, the chestnut predominating." They measuredas follows(dimensions in inches and hundredths):.81 x .57, .81 x .58, .76 x .58, .75 x .57, .79 x .60, .83 x .56, .84 x .55 and .84 x .56. The first fledglingwas secured30 June and by 20 July family partieswere noted. Carriker (1910,p. 784) describesa nest and threefresh eggs taken 8 June1907 at PuntaArenas, Costa Rica, as follows. "The nest was a beautifulstructure, very compact,and well made of weed-fibresand bark, coveredover on the outside with goldenand white spider-websand spideregg-cases, and lined with fine, roundpale brownfibres exactly after the mannerof the WarblingVireo. The eggsare white, speckled and dotted sparingly over the whole surfacewith deep burnt-umber. The nest was suspendedfrom a horizonalfork amongthe foliageof a fruit-tree of sometropical variety, aboutfifteen feet from the ground,and not more than a hundred feet from a house on the outskirts of the

In the M. C. Z. there is a set of four eggscollected 12 May 1926 by A. W. Anthonyat the FincaCarolina, 10 milessouth of Tumba- dor, Guatemala;one of the eggsis broken,the otherthree measure 21.5 x 15;21.0 x 15;21.5 x 15 mm•respectively. The collector's 580 PETERS,The Yellow-green Vireo. [Auk•.oct. notes describethe nest as "typical vireo, in coffeetree six feet from the ground." There is in the Dwight collection(no. 61037) fully fledgedjuvenal moulting into immatureplumage collected at Finca Cipres,western Guatemala, 28 June, 1925. SouthwardMigratlon.--Lawrence (1874, p. 272) quotingGrayson (Ms.) writes "none are seenafter August [at Mazatlan] migrating probablyto Central Americaafter bredding." In the large series taken by A. W. Anthony in westernGuatemala during the years 1924-1927 are five birds from the Hacienda Carolina, taken as follows: I ?, 27 September,1927; IcP, 29 September1927; I 9,30 September1927; IcP, I October 1927; I 9, 6 October 1925. In this connectionit is interestingto note that the Riverside Cali- fornia specimenwas shot29 September. Cherrie(1890 A, p. 331) writesthat the residentbirds had disappearedfrom the vicinity of SanJos• by August20th, thoughduring the night of 28 September 1889 a number of Yellow-greenVireos were among other species killedby flyingagainst wires in the city of SanJose. At the time a considerablesouthward movement of many speciesof North Americanmigrants was in progress.There is the skinof a male in the Museumof ComparativeZoology collection taken at San Jose, 7 October 1902 by C. F. Underwood. The only fall dates at present available from Panama are: 27 September 1927, a Changuinola;a 9 from Perme, easternPanama, 3 September1929 both taken by H. Wedel. Moults and Plumages.--Jtrv•m•.•.--No specimensin fresh juvenileplumage seen, but judgingfrom partly moultedjuvenals the bird has a plumagelike that of V. ollvaeeus,but the lateral underpartswith a much more extensiveand deeperyellowish wash. I•xT•Jas.--Acquired by a complete post-juvenile moult involvingall tracts exceptthe primaries,secondaries, greater wing covertsand tail. In Guatemalathis plumageis completeby the beginningof the third week in August. ADU•.TW•rsa.--Not distinguishablefrom immature plumage; acquiredby a completepost-nuptial moult beginningabout the middleof July and completebefore the first of September. Nvrr•x•..--The numberof wintering specimensavailable is not sufficientto determinewith any exactnesshow extensivethe ¾ol. 19SlXI,;VIII] ] Pm•as,The Ydlow•reen Vireo. 581 prenuptialmoult is. I have exo.rn]nedspecimens in the American Museum taken in westernAmazonia between 2 February and 3 April which were undergoinga moult of the primaries. A pre- nuptial moult of the primariesis an exceptionamong oscine birds. Dwight (1900, p. 235-240) makesno mentionof it at all, nor does Stone(1896, p. 156-157),where these ahthors discuss the plumages of the Vireos found in north-eastern North America.

Vireo fiavovirldis forreft M•R•SZ ¾ireoforreriMadar•z, Termes.Fuzetek, 9, pt. 1, 1885,p. 85, pl. 6 (Tres Mafias Islands). $•bs•c/f• Chara•rs.---Superciliarystripe indistinct, dusky border of the pileurnonly indicated; sizelarge, wing c•, 82-86.5 (83.6). Range.--Probablyonly a summerresident on the Tres Marlas Islands off the west coastof Mexico. If migratory,dates of migrationand winter home are unknown. Salvlnand Godman(1881, p. 189) first recordedthis Vireofrom the Tres Mafias Islandsunder the nameof Vireofla•rid•s. They had but a singlespecimen, a bird sent them by AlfonseForrer, whichhe shot4 May 1881. Salvinand Godmannoted the charac- ters, but did not deemthem of sufficientimportance in only one exampleto recognizeby name. Porter alsosent a specimencolo lected5 April 1881to the HungarianNational Museum. Madar•sz did not entertain the doubts that Salvin and Godman held, but named the bird as above. All that is ]mownto date of the life'historyof 17orrer'sVireo was gleanedby Nelsonand Goldmanon their visit to the Tres Marias Islandsbetween 2 and 31 May 1897. Nelson writes as follows (1899,p. 54): "It is very eommonin the smalltrees in the patioof the custom house and elsewhere about the settlement on Maria Madre. Like its mainlandrelative, its habits are very similar to thoseof the' Red-eyedVireo. Its favoriterange was in the smallergrowth of forestalong the lowerslopes from near the seaup to an altitude of 600 or 700 feet, but somewere seenup near the summitsof Maria Madre .and Maria Magdalena. Next to the •res Marias Warbler,Forrer's Vireo was probablythe most abundantbird on Maria Madre, and its restlesshabits while flutteringand peering aboutin searchof foodamong the smalltree tops added greatly to the animation of the forest." 582 r•s, TheYellow-green Vireo. [0½•.Auk

Nelson(op. cit.) expressesastonishment at the fact that Grayson did not obtain this bird on any of his three voyagesto the Tres Marias Islands. Thinking that perhapsGrayson did not visit the islandsduring the spring and summermonths I asked Dr. JosephGrinnell if he could supplyme with the actual datesof Graysoh'sthree voyages. This Dr. Grinnell has most kindly done,after consultingthe Graysonmanuscripts in the Bancroft Library at the University of California. The manuscriptsgive explicit datesfor specimensof variousbirds taken on the islands as follows: 1865, January, March, March 10 and April. 1867, April, May, June 1. No dates were found for the voyage sup- posedto have beenmade in 1866. Dr. Grinnellhas alsodiscov- ered that Graysonhad trained a boy to collectfor him, and sug- geststhe possibilitythat Graysonmight have sent the boy on shorttrips to the islandswhen he did not go therehimself. There is as yet no direct evidencethat Forrer's Vireo is really migratory,on the other hand there is no specialreason for con- sideringthat an insular form closeto the northern limit of the range of the speciesis sedentary. More weight couldbe attached to Grayson'sfailure to securethe bird in January,February and March if he had succeededin securingit in April, May and June. Perhapsthe inclusivedates of Forrer's visit, if obtainable,might shedsome light on the subject. A specimenof V. fiavoviridisin the AmericanMuseum collected 9 April in westernNicaragua has a wing of 84.5 whichis 1.5 mm. largerthan the maximumfor V. f. fiavo,iridis,and whileon basisof sizemight be referredto forreri, it is perhapsbetter to consideras the extremeof f. fia,o*iridis.

Vireo fiavoviridis insulanus B•os Vireo i•n•s Bangs, Prom N. E. Zool. CI., 3, 1902,p. 73 (San Miguel Island, Pearl Islands). SubspecificCharact•rs.--Superciliary usually distinct, but dusky border of pileurngenerally obsolete; size smaller,wing, c• 74-79, average21 c•, 76; • 71-77.5, average 13 •, 74.25. Ran#½.--TSrrabaValley in southwesternCosta l•ea, Canal Zone (chiefly Pacific side) and probably other suitable localitieson the Pacific coastof Panama; Pearl Islands (recordeddefinitely only from San Miguel Island). Probably migratory, but winter home unknown. This form wasoriginally recorded by Bangs(1901, p. 30) from SanMigUel Island as Vireochizi agilis (Liehr.) but wasseparated by him asa distinctspecies the followingyear. Its spedfiestatus remainedunquestioned until Rendaid(1920, p. 43-45) reducedit to subspecificrank. Up to now howeverno one seemsto have reeognizedthe fact that it is this race and not true fia,ovlridis that breeds in south-western Costa Riea and in the Canal Zone. A femalein wornplumage was seeured by Barbour,Brooks and Underwoodon Mt. Sapo,Darien, 25 April 1922,recorded by Bangs and Barbour(1922, p. 223) asf. fia•Jiridis. With a wing of 74 min. combinedwith its abradedplumage and entire absenceof a duskyborder to the pileum,identification as insulanus is certain. Theditterenees between this bird and a spedmen(M. C. Z. 140890) takenat Cana,eastern Panama, 20 April 1928,are very noticeable; the latter sexedas a femaleby its collector,Benson, and marked as having the ovariesnot enlarged,is in fresh plumagewith a duskyborder to the pileurnand hasa wing of 80 ram, The probabilitiesare that Barbour, Brooks and Underwood collectedtheir bird in someextensive clearing on the lowerslopes of the mountain; I much doubt whether the bird ooeursin the heavyrain forestof that region. Unfortunatelyin none of the localitieswhere insulanusoccurs as a breedingbird hasany collectingbeen done the "year around" by any one man. Rather the efforts of many have been con- centratedduring the periodof Februaryto April inclusive,though Goldmanworked practically continuously in the CanalZone from the end of December1910 until July 1911and Halllnanmade his collectionsintermittently over a periodof years. It is sigrlifieant nevertheless that none of the collectors in the Canal Zone have met with the bird there beforethe middleof February,but nu- merousinstances of occurrenceexist from thenon until May. The CostaRican rangeof V. f. insulanushas beenworked in April, May and Junewhere the bird waspresent throughout that period. Thus while the date of departureis not known and the bird's winter rangeequally unknown the datesof springarrival can be given, as well as a limited amountof informationon the subject of breeding. NorthwardMigration.--V. f. insulanusarrives on its breeding 584 Wro. Auk groundin the Canal Zone and the Pearl Islands,and probably also southwesternCosta Riea, ahead of the main flight of V. f. fia,o•irldis. Actual dates based on specimensare as follows: Canal Zone: Empire, 1 c•, 14 February 1912, ]g. A. Goldman. Hallinan (1924, p. 324) records(as V. f. fia,o•iridis) a c•, 21 February1916 from Juan Mina, C.Z. This specimen,now in the American Museum, has been examined in this connection; it provesto be insulanus. Pearl Islands: San Miguel Island, 1 c•, 1 9, 16, 17 February1926, L. Griseom,specimens in American Museum; 2 c•, 23 February 1904, W. W. Brown. Goldman secureda 9 at Tabernilla, C. Z. 10 March 1911 and Brown took additionalspecimens on SanMiguel Id. 3-17 March. Mr. Griseom has generouslysupplied me with the dateson which he has seen Yellow-green Vireos in Panama. Since observations are not supportedby specimens,it is by no meanscertain whetherin- sulanuswas the bird in every ease,though it is probablethat the bulk of them are. February 1924: 14, Artcon; 15, Old Panama; 17 Taboga Id., 21, Santiagode Veraguas"common"; 25, Tole, "common";27, Remedios"common." February1926: 15, Aneon. V. f. insulanushas never previouslybeen attributed to the Canal Zone, but has been recordedas fiavo•rldis on several oc- casions.I have beenable to examinethe two birds recordedby Hallinan (1924,p. 324) and find them to be insulanusas is likewise the specimencollected by Jewel at Agua Clara, 19 May 1912 (Stone, 1918, p. 273). Unrecordedexamples definitely referable to this subspecies,were secured by Goldmanin the Canal Zoneas follows:Tabernilla, 18, 20, 29 April 1911; Gatun, 22 April 1911; Frijoles,9 May, 1911;Miraflores, 13 May 1911. Nesting.--Thereis practicallyno informationavailable regard- ing the nest dates or eggsof this subspecies.The plumageof Pearl Island birds collectedin late April is muchmore abraded than that of examplesof f. fia,ovlridistaken in Mexicoand northern Central America at the correspondingseason, indicating that breedingon the islandsat least commencesa coupleof weeksor moreearlier than on the mainland. Underwoodtook fledglingsin the T•rraba Valley, Costa Riea, 23 June 1908 and 25 June 1906. SouthwardMigration.--No data available becauseof lack of field work in the breedingrange of the subspeciesafter 1 July. 585

Moults and Plurnages.--Probablynot different from those of V. f. fla•ovirid•s. A bird collected23 June,1908 hasthe •mm•ture plumage partly complete,but with some juvenile feathers on the head, scapulars,interscapulars and throat, the yellowflank feathersnot fully grownout. Anotherexample from Barranca, Borucashot 25 June 1906'has the immature plumage fully devel- opedexcept for scatteredtraces of the juvenileon backand nape. An adult (sexnot determined)collected by C. F. Underwoodat PasoReal, Boruca,14 July 1906has nearlycompleted the moult, part of the bodyplumage is freshwith manypin feathersscattered through;the primarieshave beenrenewed, but the two outermost are not fully grownout; the t•il has alsobeen renewed but only the two middlepair a•e fully grownout, the outer pair is but a little morethan half as longas the middleones.

LIU•ERA?URE CIU•ED. BAsos, OWrRXM. 1901. Bi• of •n Mi•el Is•nd, P•. A•, 18, 1901, p. 2•2. 1•2. T• New B•s from •n Mi•el •nd, Bay of Pa•. •. New Eng. •ol. Cl., •, p. 71-73. B•, O• • B•o•, •o•. 19•. Bi•s from D•en. B•. M•. Comp. •ol., 65, no. 6, p. 191-

BOUC•D, •OLP•. 1878. On b• coHec• in •s• •. •c. Zool.•c. •ndon, p. 37-71. C•sms, Jo•. 1851. Proc.A•d. Nat. •i. P•adelp•, •, p. 14•154. C•R, M. A., JR. 1910. • annoyed •t of the b• of •s• •ea •elu•g •eos I•d. •. C•e•e M•. 6, n•. • p. 31•15, •p. •M•, • M. 1917. •e •t•bu•on of b•-•e • •1omb•. B•I. •. M•. Nat. H'•t., 36, p. I-X • 729 pp., 51 pl., 21 • $. 1926. The d'•bution of b•d-•e • •or. B•. Am. M•. Nat. H'•t., •, p. I-•II • 784 pp., 30 pl. (•cl. •p), 20 • $. CHE•E• GEORGEK. i8•. No• on •blts and nes• of Vir• •o• C•. A•, •, p. 3•331. 18• A. Noah Ame•n b• fo•d at San Jos•, •s• •, • no• on •e• •a•on. A• •, p. 331-337. •E, •oN J. 1•6. Ver•bra• from Yu•n; Ave. B•. M•. Comp.•oI., •0, no. • $•), p. 10•1•. 586 PETERS,The Yellow-green Vireo. [oct.Auk

DEARBORN,NED. 1907. Catalogueof a collectionof birds from Guatemala. Field Mus. Nat. Hist. Publ, Orn. Ser., 1, no. 3, p. 69-138, map. DWIGHT, JONATHAN,JR. 1900. Sequenceof moultsand plumagesof passerinebirds. Ann. N.Y. Ac. Sci., 13, p. 73-360. GADOW,HANS. 1883. Catalogueof the Passeriformesor perchingbirds in the collection of the British Museum. Paridae; Laniidae; Certhiidae. 8, i-xiii 385 pp., 9 pls. •-IALLINAN, THOMAS. 1924. Notes on some Panama Canal Zone birds with specialreference to their food. Auk, 41, p. 304-326. JouY, P. L. 1893. Notes on birds of central Mexico with descriptionsof forms believedto be new. Proc. U.S. Nat. Mus., 16, p. 771-791. LAWRENCE,GEORGE N. 1874. The birds of western and northwestern Mexico, based upon the collectionsmade by Col. A. J. Grayson, Capt. J. Xantus and Ferd. Bischoff, now in the Museum of the Smithsonian Institution at Washington, D.C. Mere. Boston Soc. Nat. Hist., 2, no. 9, p. 265- 319. 1876. Birds of southwestern Mexico collected by Francis E. Sumi- chrast for the United States National Museum. Bull. no. 4, U.S. Nat. Mus. p. 5-56. MERRIAM, C. HART. 1883. On a bird new to northern North America. Bull. Nuttall Orn. Cl., 8, p. 213 (specimenpicked up dead at Godbout, Quebec, 13 May 1883). MERRILL, JA•ES C. 1878. Notes on the ornithologyof southernTexas, being a list of birds observedin the vicinity of Fort Brown, Texas from February 1876 to June, 1878. Proc. U.S. Nat. Mus., 1, p. 118-173 (Vireosylva.fiavo- viridis •, Fort Brown, 23 August 1877). MADAR•.SZ,JULIUS V. 1885. OrnithologischeMittheilungen fiber die Sammlungendes garischenNational-Museum. Termes. Fiizetek, 9, p. 84-87, pl. 6. M•N•GAUX, AUGUST. 1911. Mission du Service Geographiquede l'Arm•e pour la roesure d'un arc de m•ridien equatorial en Amerique du Sud etc. 1899- 1906, 9, Zool., fast. 1. NELSON, E. W. 1899. Birds of the Tres Marias Islands. North American Fauna, No. 14 (part), p. 21-62. ¾ol. 1931XL¾III] J PETERS,TheYellow-green Vireo. 587

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