Ar.CID.K — Till", Al KS. 



401 



tlif Viikoii Kivcr, Sitkii. AmlrrMiii Itivcr. ami (iirciiliiiiil. 'I'lif K''"im"l-t''>l<>'' varii's 

 Iroiii ;i (ItM'p rt'ililisli ihiiImt. nr a (li'i-p raw iiiiiIht, tn a i,'iavisli j,'n'i'ii. Tlic iiiaikiiij,'s 

 arc usually sniall, sparse, ami dI a i>i(>\viii>li iijaik. Tlii' r;4^'s vary in tlu-ir length 

 iium I'.Oo to 3.00 iuelu's, ami iu tlu-ir ijicaillli Iniiu 1.70 to l.So. 



F.wm.v AL('Il>.i:. — TiiK At i<s. 



C'll.Mi. Swiiuiuinj,' liinis with the f»'ct siluatctl tar hack, tiic niilcrior toes fully 

 wclilicil, ami aiiiH'il witli stioui,' <'la\vs, the hallux fuliit'ly ahscut. Lures fcatli- 

 LTfil ; tail normal, always short; in»strils without ovt'riiaii^'in<,' iniuuiiranf. Itill 

 I'Xfossively viiriahU> in form. 



The iil)ove diajjuosi.s, thoui^h lirief, is ipiite .sutlieieut to (listinj,'uisli this I'auiily 

 from that most nearly rehiteil — the rriinifurii/ir — whieh dilTers essentially iu th« 

 possession of a well-developed hiiid toe. and in the nosti'ils iieinj; overhung; hy ii 

 nu'inhrane. The ditTerent f^eiiera e.\hil)it remarkahle extrenu's of form, espeeially 

 (d' the hill (the variation of other parts In-iu},' etimparatively trilling), and, to ii less 

 extent, of si/e. 



All the fjem-ra. and most, if not all, of the species, arc American, the family heiu^j 

 (d" circumpolar distrihutiou, with few. if any, forms pcinliar to cither coutincut, the 

 chief dilTcrcuce hciuf; iM-twcen the North Taeilic and North Atlantic representatives. 



Followiuf? is an arianijemcnt of the j^eiiera which is ix'licvcd to express very m-arly 

 the natural alHuities of the various forms: — 



A« Imicr tliiu norniid (md liii'jiur or iiion- rurvcil tliaii the niluis). No timiid "rosotte" nt iui;;ln 

 of nioulli. 

 d'. Mental apex nuicli nearer to tip of lijll than to nostril ; rarotiil single (double in all other 

 Alriihr, HI) far us known). 

 Siil)-fannl.v .Vi.i.ix.K. 



1. AUe. Iiill short ami very hroad, the wiilili at the liase about eipial to tlio (le|)th ami to 

 the (listani'e from tin- nostril to tlie ti|i. Nasal o|K-ri'ulmu eoiapletely exposed, (iniiys 

 very short, l>einj{ less than the width of the spaee iM-tweeii tliu iniuulihalur rami at ii 

 point innnediately iH-neatli the nostril. Si/e small (win^ less than .').(KI inelies). 

 (('. Mental apex nmch nearer to iio-tril tlian to tip ol' l>ill. 



/)'. Suli-family Ai.ctN.t:. Nasid l'os>a' eompletely lille<l with deiiso velvety featheriiif;, extend- 

 ing to or lieyoiid anterior end of nostrils, 

 f*. Itill very deep, the t'ulnien viTv >troni,'ly ronvex, tlu' maxilla (sonietinitw mandible 

 also) with very distinet nbliipiely tr.msver>e ^'rooves. Tail ^Taduated, tiie feathers 

 jiointed. (Ali'iir.) 

 •2. Plautus. Largest of the AUiihr. Wind's ruilinieiiiary. not admiltiu;^ of llit,'lit. Itill eipial 



to tlie heail in len;{tli, the niandil>li' willi niiMnniiis transverse suiiations. 

 ."{. Aloa. Size nie<liuni. \ViM;.;s well develoiMil. adiniltin^^ of sustained lli^ht. Itill nmeh 

 uliortiT than head, the mandible with biu one or two well-detined sulci (or none), 

 c". Hill more slender, the rnlinen slij,'hl!y nr ;^ently convex, bnlli nianclil>les destitute of 

 transverse p-ooves. Tail roiuidi'd. the I'l-athei-s not pointed. (/ViVir.) 

 >. Uria. Si/.e of Alit. 



h*. Sub-family Piiai.kui.v.K. Nasal lo^se oidy partly leathered, the leatherinj,' never reaching 



anterior end of nostrils, tiie nas;d o|H-rcnlnni always eonipletely exposed. 



c*. Hill Hiender, compresseil, nearly as Ion;; ns the head, the enlinen straight to lu'ar the 



tip, wheit! abruptly tiecurved ; ;,'onys nearly stnii^'lil, ascending; to tlie tip I'rtau the 



nnnle, which is situated nearer the tip than the base of the inandilile. Loral aiKiX 



forming' uii acute angle, (i 'rpi'heae.) 



