44 ox CEETAIN OEKITHOSAUEIAN AKD DIXOSAUEIAlSr KEMAIKS. 



type vertebrae of CaJamosaunis Foxi pertained; but, since it was 

 obtained ap2)arently from the same bed as the latter, there is a 

 probability that it may have belonged to another individual of that 

 species, to which I propose to refer it provisionally. Since Coelurus 

 Daviesi is still larger than the type Calamosaurus Foxi^ it is unlikely 

 that the present specimen belonged to that species. 



In his description of the femur of Megalosaurus^ Professor 

 Huxley * commented upon its extremely bird-like form. These 

 avian features are, however, still more intensified in the present 

 specimen, which may be compared with the slightly smaller tibio- 

 tarsus of Apterxjx Oiueni. The whole bone is relatively longer 

 and more slender than the tibia of Megalosauriisf, its fibular 

 ridge is much longer and more prominent, and the distal extremity 

 is still more flattened. Even more remarkable is the great upward 

 extension of the facet for the ascending splint of the astragalus, 

 which reaches fully an inch up the shaft. The sharp ridge forming 

 the inner border of the distal part of the surface for the astragalus 

 corresponds to the ridge bordering the outer side of the extensor 

 groove of the tibia of Ajpterycc, and thus still further intensifies the 

 avian characters of the bone. 



The present specimen is, indeed, the most bird-like Dinosaurian 

 tibia that has come under my observation; and, in conclusion, 

 attention may be directed to the very curious feature — that, whereas 

 the OmitJiopoda make the nearest approach to the avian plan of 

 organization in the structure of the pelvis, it is among the TJiero- 

 poda, so far as regards European types, that we find the most avian 

 characters in the structure of the hind limb. 



EXPLANATION OF PLATE V. 



Figs. 1 a, 1 b. Left lateral and anterior aspects of a ceryical vertebra of Calamo- 

 saurus Foxi ; from the Wealden of the Isle of Wight, s, neural 

 spine ; 2^'''~, prezygapopbysis ; ;ptz, postzygapophysis ; r, cervical rib ; 

 ./', pneumatic foramen. 



Figs. 2 a, '2 b, 2 c. Anterior, distal, and posterior aspects of a right tibia referred 

 to Calamosaurus Foxi ; from the Wealden of tbe Isle of Wight, a, 

 inner condyle ; 6, outer condyle (broken) ; d, cnemial crest ; /, fibular 

 ridge ; as, facet for astragalus. 



Fi^s. 3 a, 3 b. Posterior and distal aspects of tbe right quadi-ate of Rhamphorhyn- 

 chusMansdi\ from the Kimeridgian of Dorsetshire, q, quadrate; j??i^, 

 pterygoid. 



Figs. 4«, 4 6. Posterior and distal aspects of a right quadrate referred to 

 Bharaj)1iorliijnchus supra-jurensis; from the Kimeridgian of Dorset- 

 shire. 



All the figures are of the natural size. 



* Quart. Journ. Geol. Soc. vol. xxvi. p. 102 ef seq. 

 t Huxley, op. cit. p. 20, fig. 1. 



