286 



NEW YORK STATE MUSEUM 



within the grasp of the hinder ends of the iliac bones, whereas in 

 the teals this segment is found one vertebra's length behind them 

 or entirely without their grasp. It will be seen, however, thai, this 

 does not affect the total count, it remaining 44 for the first named 

 genus and but 43 for the teals and the garrot. I mention this 

 because specimens of Spatula and Clangula may be found where 

 this 38th vertebra has united with the pelvis, as from the position 

 it occupies it is perfectly possible for it to do so. 



In Olor col umbi anus the arrangement is entire 1 } dif- 

 ferent. Here we find the series leading off with one pair of free 

 ribs (on the 23d vertebra), followed by nine pairs that connect 

 with the sternum by costal ribs and completed by a floating pair 

 that neither joins with the pelvis above nor. the sternum below. 

 This gives the swan 11 pairs of ribs. Of these, the first and the last 

 four are without unciform appendages. In those ribs where they 

 do occur they are anchylosed to them and are not notably large. 

 The last four pairs of ribs come from beneath the ilia in this swan 

 and curve far backward, reminding us of a condition that is still 

 more pronounced in the loons. Nor is this the only feature in 

 Olor wherein it resembles that family, as we will see further on. 



This swan has a low median hypupophysis on each dorsal 

 vertebra, and the neural crests of these segments are comparatively 

 low, being laced together by long spiculae as I have already de- 

 scribed them for the ducks. 



It has been noticed above that in H a r e 1 d a h y e lira 1 i 3 

 both the vertebral and costal ribs are markedly lengthened, as we 

 pass in the direction of the pelvis, in a manner similar to* what is 

 seen in most all auks. 



This particular feature, to a large extent, is present also in 

 S o m a t e r i a m o 1 1 i s s i m a and in O i d em i a d e g 1 a n d i , 

 but not especially noticeable in O i d e m i a perspicillata, 

 and by no means a striking feature in other ducks that I have 

 examined. In Clangula it is associated with a peculiar form of 

 sternum not seen either in Somateria or Oidemia, and this form of 

 sternum has a distinct resemblance to that bone as we found it 

 in Gavia lumme, and in this diver be it remembered, the 

 ribs also sweep backward in long and graceful curves mucli as 

 they do in the auks. 



In the cervical region of Somateria mollissiina I find 

 the neural spines but feebly developed in the first six vertebrae, 

 to become entirely absent in mid series, not to appear again until 



