»KI>S OF THE OREGON DESERT. 
1 tlie corresponding part in that specimen and 
tertiary ei«K-l. »f that region Professor Cope. 
KuMtil nijfciiiieii collected in saint locaiuy uj i , • ,1 tt. 
TrijU ing SUgam/^cl^s, thon. occurred or p.-obably occurred m the Equus 
Ueilt of ()n*gon : — *• f \ 
Fhahuroeorax macropus (numerous and now extinct.) 
PtUcauus trythrorhynchos ? 
ANSERES. 
A gn-nt innnv HiK*cies of existing forms of Swans, Geese, and Ducks at the 
,.n‘m.nt time res..rt unminlly to Silver Lake during the migrations, so ive would 
iintumllv lo»»k for numerous siiecies of the same group in a locality where fossil 
fumis ufliinls so iibumlantly occur. In this there is no ground for disappointment, 
and ill the tHiUwtion now in liand the Auseres are well represented. 
Mon- or fewer of these are found to be identical with western species now 
cxhiing, while sevenil closely allied six-cies have become extinct, and in one or two 
instniMvs very dilfen-nt tyiH-s have shared the same fate. It seems to be in the 
naliiml onh-r of things that large bulky fonns of any group of vertebrates sooner or 
Uti-r ilisap|>ear fnnn the face of the earth, hut it still remains quite problematical why 
Nil Nvemge sijuil Duck, a go<Kl flyer, living on the same food as its immediate kin, 
and nothing |MH'uliar alsiut it, should, with more or less suddenness, so disappear. 
Itiit that such cns«-« have iHicurreil, and are continually occurring, there is no doubt; 
to cite n well known instance one has but to mention the remarkable case of 
extinction exeinplifnHl in the laibnulor duck {Camptolawius labraciorius). That 
hinl, ns is well known, cpiite sudilenly iK-came extinct upon our North Atlantic 
(ViNst, anil, ns it were, under the very eyes of all ornithologists. No adequate 
reason for its disnp|H>nmnce has yet lieen furnished. With this example before us, 
no one would at the pn-sont time exjH-rience any' surprise were.any other one of 
our eoiniiioii s|H-cies of ninH.-rine fowl to disappear in the same manner. Having the 
history of Cafuptolamus 'm my mind, when I came to study the fossil Afiseresonh^ 
«lver Uke region I naturally looktnl for at least a number of species that had long 
since «-nse«l to exist, and ujHui completing that study felt no small degree of sur- 
prise III finding s.> iiiaiiy fo.ssiI forms which, in so ftrr as their osteology was concerned, 
apiH-an-.! to U- identical with those Auseres still in existence in our avifauna. 
in tin K O il'i* "r?’. ^F'^Jes which have thus for been discovered 
« I-s,uus Ik-ils of ()n.go„, „„a they are all represented in the present collection. 
Ix>ninl>TTRS t-fCl I.I.ATrs. 
f°.;rc„rac„id. an ...e ngi.. aide, 
e erganser. Upon comparison they’ ai’e found 
