65 



vex transversely and gently convex longitiulinally. A peculiarity consists of 

 a central cavity present in both at the fractured large end, which is bordered 

 by a layer of dense bone like the outside. 



Measurements. 



M. 



Transverse diameter of the tibia-fiagincnt below the cuemial crest 0. 125 



Autero-postcrior diameter of the tibiafragmeut at the base of the crest 0.095 



Width of the fragment of the iibiila 0.073 



Thickness of the fragment of the fibula 0.035 ^ 



Length of the fragment of an unknown pelvic bone 0. 145 



Proximal diameterof the fragment of the unknown bone 0.088 



Distal diameter of the fragment of the unknown bone 0.065 



The above measurements indicate a much larger animal than the Ciono- 

 don arctatus, and are not very different in size from the Lcalaps aquilunguis. 



ORNITHOSAURIA. 



As compared with the European Cretaceous, the corresponding beds in 

 North America have yielded but few species. These are of the largest size 

 to which species of the order are known to attain. To Professor Owen and 

 H. von Meyer, science is indebted for the first explanations of the structure 

 of these remarkable reptiles ; while Prof H. G. Seeley, of Cambridge, En- 

 gland, has added greatly to the work commenced by the elder authors, and 

 also extended our knowledge of the genera and species. 



PTERODACTYLUS, Cuv. 



Pterodactylus umbeosus. Cope. 



Represented, by, the distal portion (ten inches) of the wing-finger meta- 

 carjjal ; the proximal portion (eight inches) of the first phalange of the same 

 digit, with a lateral carpal, and two phalanges of claw-bearing digits. I'he 

 distal condyles of the first-named bone are separated by the usual deep groove 

 above and below, and wind spirally to their terminations on the inferior face. 

 The narrow base which supports the inner condyle is bounded posteriorly by 

 an acute edge ; directly outside of the base of this ridge is a deep groove or 

 foramen, which is bounded next the external condyle by another ridge, which 

 rises to the base of the inner condyle on the trochlear side. The transverse 

 diameter of the condyles is O^.OiS, or 17 lines. 



The proximal end of the first plialange is perfect, but flattened by press- 

 ure. It presents the two usual cotyloid cavities well separated by an ele- 

 9 c 



