90 MB H. a. SEELET ON THE 



aviaatjpe of structure exhibited by tbe skeletons of Pterodactyles 

 are as important as tbose in the cases cited have been. 



First, as to the structure of the skull and vertebral column. 

 Von Meyer has remarked on the preponderating resemblance 

 to the bird's skull shown in the skulls of Ornithosaurian fossils 

 from the lithographic slate of Germany; and elsewhere I have 

 translated his exposition of their characters*. But although he 

 states the several bones, as well as their texture, condition, and 

 arrangement, to be avian, he does not mention the particular birds 

 with which comparison may be made. Some of these comparisons 

 I will supply. 



If our attention is turned to the skull, seen from above, as in 

 the published figures and casts of JRhamphorliyncJius Gemmingi, 

 the outline of the skull is a long triangle terminating sharply in 

 front, similar to that presented by the skull of the great African 

 Kingfisher {Geryle maxima), in which the positions and propor- 

 tions of nares, orbits, and temporal fossae correspond closely, the 

 differences being that the Ornithosaur has no premaxillary facial 

 joint, and the bird has no complete temporal fossa. The common 

 Heron {Ardea cinerea) also resembles the Pterodactyle in the fore 

 part of the head, but behind the eyes it has the skull both longer 

 and larger. 



If the comparison is made from the side view, the small back- 

 wardly placed nares and complete orbit of RhampTiorJiynchus 

 Gemmingi show some resemblance to these organs in the parrots. 

 The orbital circle, however, is formed in different ways. An in- 

 teresting resemblance, both in the position and proportion of the 

 several regions of the side of the skull (nares, orbits, cerebral 

 space and quadrate bone), may be noticed on comparing Ptero- 

 dactylus lonyirostris and P. scolopaciceps with the Bar-tailed 

 Godwit {Limosa lapponica). The quadrate bone is similarly in- 

 clined forward in the Curlew, Snipe, and other birds, while it 

 articulates inferiorly with the squamosal region of the brain-case, 

 as the quadrate bone articulates in birds and in no other animals. 

 When a bird has a circular orbit for the eye, the circle appears 

 to be completed below by a downward and backward growth of 

 the lachrymal bone uniting with a forward growth of the frontal 

 bone in its postfrontal region. Many water-birds, especially the 

 Maned G-oose {Bernicla jubata) , the Swan,°and the Teal, show an 

 approximation to such a condition. The Great Bustard, too, shows 



* Ann. Nat. Hist. 1871. 



