ON C'VrUOKNIS. AN EXTINCT 
.• .. IL.tu-.HMi the hvpotar.sal ridges is a groove in the 
te„ckm of the Hexor digitorum muscl^ 
..lU, .1... tlH- “f S’'""'- ">y te 'l"--- »ned. 
K«u.n..l lo tl,. i» tlu- Imm.l !.»«. tl.o extimal hypotarsal ir«t. It» sulv 
.l«,™ i. ««.~ ly .•.•llular, i. n-t t ravers...! by any gro.»ce. Its .nlcrior ex. 
InMuily i- hut little lieluw the transverse- line of the inteni.al i>osterior intero-ssettus 
formiiK-ii. Kxtemal t.. it is n seeon.l groove, which is narrower than the gnxtve 
pit-vienisly il.-scriM. and it is ls.iin<letl exteriiallj by a well-defined, but low ridge, 
whirh is cHiiivex |i.»steri»»rly at the inferior part of the groove. PVoin this ridge the 
external siirfatv is gently eonve.v to the antero-extenial. Between this gnx)ve and 
the iiirerior |*art of the external hyiMitarsal mass, is an oval foramen, its long axis 
|Ninille| t<i that «if the lajiie, pnil>abiy the external intero-sseons foramen. The sur- 
fsrr of the Isiiie is every when* siniMith. 
.Mk.\.s| KK.MK.\T.S. 
.\rliinl transverse pmxiiiiai .liaineter; 
l{f«|tin'<l diaiiielers of liliial faces 
when* Imtken 
M.M. 
38 
22 
44 
21 
24 
17 
5 
6 
3 • 
( anteroj>ostt.*rior ; 
I transverse ; 
IHameien. of sliaH when* Im.ken j «"teroi>osteri.,r, at middle ; 
I transverse; 
I Haiiieien. of niilerior pneiimatie rorainen ^ ! 
I transverse ; 
Wnlth of Iwse .if external hy|HitarsaI crest ; 
of iNiseof iiitemni hv|s.larsal cn*8t; 3 
Kn.i,, «,M.x orinten*.«Hlylar tiilM-rosity to internal ix.sterior foramen (axial) ; 20 
somewhat emharra8se*d bv the 
u 7 s ne ."'“.T- L 'Their very coarsely cellular char'acter 
1I.0 .,n,.^r Z iZn" Pid" p". tins bone with 
eipilres, f’et'oiiiiirtilin. f*i . ^ '*^oyge.s. Psittaci, Iletcrosmnidyli,* Ac- 
.» ...|«.rfivin|. lw\rnZ’'irit”it ,lit"..''^“'^ ‘''""'"i' , 
the first Iiam, Ml. this g,.„„^enn only Ik* P.. ^teganoiKules. Among 
crests, which an* the lUieidn* V.m.rv ' 1 h> the genera with two hyjx.tarsal 
IhmwnilhHln* the lanminelalarsi. I ff ’ Ih'nornithida'. From tli.at of the 
Urge .*iirl.«s.M| pneniiiatic cavity withmit" ^ t«'>mity of its walls, and the 
I'cniof the other families it differs in ii y*'**^^‘ ****** From the known niem- 
*uigle anterior: ami iM.|a*einIlv imsterior pneumatic foramina, and 
' • ■" minced six.. „r .l,c eorrespnd- 
•n*. \Vrtrt.«,.. J„,y. , 
1. 1>. .W (Hteai..rnithlda!). 
