SAirRORNITIIKS r,:]5 



(3) There are apparently free cervical ribs, and the 

 thoracic ribs have but one head. 



(4) The sternum is absent or w^eak (?) . 



(5) There are abdominal ribs. 



(6) The number of phalanges to the fingers of the hand 

 is as in reptiles. 



(7) The constituent bones of the pelvis are separate. 



(8) There was no beak. 



The Archaopteryx also differs from all birds excepting 

 those specially mentioned in the foUovs^ing characters : — 



(1) The jaws are toothed (also Hesperornis, IcKthyornia, 

 Laopteryz ?). 



(2) The ribs have no uncinate processes (so in Cliauna, 

 Palamedea) . 



(3) The metacarpals are free (also Gastornis). 



It is, furthermore, supposed that the bones were not 

 aerated, no pneumatic foramina having been discovered. 

 This would militate against flight, and there are other facts 

 of structure that indicate at most a feeble power of flight. 

 It must, however, be observed that the series of rectrices was 

 apparently continued along the sides of the body, and that 

 the tibiae seem to have borne strong quill feathers. From 

 this Hurst infers that the Archceopteryx was ' fitted for 

 flight, if not for prolonged flight.' But though it has an 

 ' insessorial ' foot it seems doubtful whether the attitude 

 when at rest was not quadrupedal. The heavy head and 

 neck and the slenderness of the hind limbs would tend to 

 throw the centre of gravity further forwards than in recent 

 birds, HuEST thinks.' 



As an appendix to the present group may be mentioned 

 the very imperfectly known Laopteryx — not on account of 

 any definitely ascertained resemblances, but merely by reason 



' Dames, ' Uber Archeiopteryx,' F(f,laonl. Abhandl. ii. 1884, is the principal 

 memoir upon the bird. Back, in Zool. Am. ix. p. 106, has summed up the 

 literature down to 1886. Since then HrnsT and Pykcraft have written iiprn 

 Archaoptertix in Natural Science, vols. \. vi. 



