36 



THE AMKRICAX NATURALIST. [X'. .1. X X.W 1 I I . 



In Cn'fiator nnlh r the I is by no means as ])roa(l as ]t is m 

 [ . Invwic, the ui)per expanded i)arts are e\en still thinner, and 

 relatively somewhat laruer. and tinalK', it totalU' lacks the h\ po- 

 cletdium. All this a<;Tees with the os Ivireula ot the loon, the 

 skeleton ot which Cones described {loc. at. \). 148). 



Ihe coiacoid ot T imln, x.n ck.seh a^ue-^ uith that bone 

 as we find it in i . Inuiinc, but the toramen that i)ierces the scap- 

 ular process m imbci\ is a constant teattire m that six-cies. The 

 scapulae of these two divers are essentially quite alike, excei)t in 

 jxnnt of size. A point to be noticed in this latter bone, is the 

 fact that the head and neck is bent at a rounded am;le. with 

 j^reater or less abruptness with the continviitv ot the blade ot the 

 bone. This flexure {U. Inmme, Spec No 1:1646 eoll I S 

 Nat. Museum) is ^?reater in one scapula than it is m the i»ther: 

 the an^le bein<^ more acute upon the left side it \er\ open 

 in other specimens. 



In Ihspnoniis u>n/,^ the cLukIl. m the adult did n<.t lus. 

 with each other at the middle point below, siniph artic ulatin- at 

 the pomt ot contact. I his is the condition of those b<.nes in the 

 \ei) >oun^M)t i iniatoi an unbn . mu conditmn. it uiu. 



Comparatively speaking-, m all the loons, we find the sternum 

 to be a very lar-e bone. It is twice as l.,n- as it i^ broad, and 

 it has oieat tiiangulai costal pioces-es \n ^xtenMN. o\al 

 notch on either side ol the keel behind -i\es rise t.. lateral 

 xii)hoidal pioccsscs, vNhile the mid-poi tion. .h iped iik. a shidd 

 01 an escutcheon, extends consideiabK nu.u p..stuio,K, and 



manubrium is broadlv wed-e-shaped and" nearlv aborted; its 

 tiian^ulai. antuioi tac . is sh^duh conuuui e ost d ^looxes 

 ate long and dee]), but lelativel), not as dee]) as the\ are in the 



