678 



STERNA FORSTERI, FOKS lEK S TERN. 



Differential iliagiiost-s of S. ./orsfcii. hiruiido, and macriira. 



S. forsteii : Bill ^;ivorii<;e), l.OH iildiis' ciilinoii ; doii'lli ;\t l):i,so. 0. Id; mlmsl. Bill 

 orange-yollow, noiul.v lis (oniiiiiHl lialf bhiok. Wliiti' spnci' liolwi-rii oxo luiil onlliiitt 

 L'dgo of upper uiiimliblo bvoad. UiuUm' parts wliito. Ouirr web of liist iniiiiaiy sil- 

 voiy; the iuaer wobs also ol" t!io ollu'is strongly lioary, without woll ib-iiiu'il wbilo 

 spaces. Tail bluish-pearl, like the baek, its lateral leather i;reaHy pnnliieed (,a\i-ra,i;e 

 uoiu'ly 7 iuehes iu length) ; its outer web w bite, inner the eolor ol the rest ol Ihe tail. 

 Legs long aud stont. ' Ijengtb ol' tarsns (a\ i>rage) rather over 0.90 of an ineli ; orange- 

 yellow, tiuj^ed with vermilion. Lenglli of tarsns. middle toe and elaw, !i inches. 



.*•'. hirimdo: BilUaverage), 1. 1.", along enlnien ; depth at base. 0.;i:l ; moderate. Mill 

 vermiliou-red, its terminal third hlaeU.' White spaei> betwei-n i>ye niid enlting edg(^ of 

 ti)iper maudible narrower than iu fomtiri. Uuder parts lightly washed with plumbe- 

 ous, fadiug into white ou tlu' throat and abdomen. ()nti>r wcl) of first primary Idaek ; 

 inner webs of the others ,sonu>what lioary, with well-d<<liiied white spaees. fail wliile, 

 diflereut from the haek. its lateral feather moderately prodneed i,average(i inelies in 

 length); its outer web grayish dusky, inner white. Legs moderate. Length of larsiis 

 abiuit 0.80 of an inch ;' light vormilion-red. Length of tarsns, middle toe and elaw, 

 LTo inches. 



.S'. maenira : Bill (average), l.;U) along eulinen; depth at base, O.iiO ; slend(>r. Bill 

 wholly deep carmine-red. White space iii'tween eye and cutting edge of upper mandi- 

 ble narrower than in liiniiido. Under parts deeideilly pluinlu-ous, e\li>iidiiig froiii vent 

 to throat, both of which beeoinc iibruptly wliite. rriinaries as in hiniiiiUi. Tail with 

 the elongation o( forstcri, or rather exceeding it (average 7.i">0 inelies), and the color of 

 liintiido. liCgs very short and slender. .Length of larsiis (average) 0.0^ of an ineli; 

 deep vermilion, almost lake, licngth of tarsns, middle toe ami claw, about l.fiO ini'lies. 



ComiHirinoii of the \iiiiiiiii-i\f-llii-\jitir of .s'. forslcri iind hiruiido. — The bill ami feel con- 

 stantly present dilfeieiiees proportional to tluvse which exist in tl'.e lulnlls, as r<'gard8 

 length and stoutness. The hill of hiriiiido is more decidedly yellowish at the base of 

 the lower mandiblci than in that <A' J'orKlcii, and tlie feel are clear yellow iimtead of 

 being tinged with dusky. The mottled and variegated crown and Ujipcr parts are iiiueh 

 the same in both, and the markings of the quills iiiiile ideuticiil. The tail, however, 

 ditl'ers remarkably. In liiruiido the enter webs of all the feathers are dusky tfray. Iu 

 fitmlffi the revi'rso is the ease. The dilVereuee is even more marked than ill the inlnlts. 



Sunvni/iiii/. — This species was ilrst indicated by Swainson and Ivielnirdson, as above, 

 uuder tlie iianie of KIrnia hiiiiiulo, these aiilhors, liowcvi'r, appreeiiitiing and eoiii- 

 meiiting n)Hiii the dill'erences from that species. Nutlall was the lirsl, to give it. a spe- 

 ci(l(^ name, based upon the indications alloiili'd by the aiilhoi's above mentioned. To 

 llr. (.1. N. Lawrence, liow'(>ver, is really due the credit of first establisliinjj; the spei ies 

 by giving eoiiiplete descriplious, and of showing its rivlat ionsliips to iS', hirmiilo. This 

 niisa|iplicatiim of Linna'ii.s' iiaiiie by Swainson and hichardson is, I believe, the only 

 spccilii^ synonym (excepting Amlnbou's " luu'elli"), nulcss the Sti-nui indltdli of Null all's 

 w'orU (from Audubon's Jlss.) is to bo reierred here, as is probably the case. In Iloiia- 

 jiarle's fable of .Longipeunos (('. h'. xlii, isrili, ]). 7(i.S) not, only is lidrcUi seiiarated spe- 

 eiUcally tvomfoi-nlfri, but it is jilaeed in a dill'erent genus ((Irlochfliildii,), wtiilo Inididiii 

 is made a Tli<ihrKi«iin. It is dillicult to aceouii» for such a, misapprehension of tin ii' 

 allinities, hut vagaries of this sort are too often found in the latest, works of this illii.s- 

 trious author. It is nnneeessary to reiirodiice hero I, he argiinient by which I showed 

 (I'r. A. N. S. I'liil. ISli-J, p. M'A) the identity of /i(ti'c//i and /iirnliri, for the fact is fully 

 established. 



I append the measnreuiouts of several speoiinens of /oi'n/cri, showing llie limits of 

 its variation iu size: 



