H. G. SEELEY ON THE FEMUR OE CRYPTOSAURUS EUMERUS. 149 



11. On the Femur of Cryptosaurus eumerus, Seeley, a Dinosaur 

 from the Oxeord Clay of Great Gransden. By Harry Govier 

 Seeley, Esq., F.L.S., F.G.S., Professor of Physical Geography 

 in Bedford College, London. (Read December 2, 1874.) 



[Plate VI.] 



This femur, presented to the Woodwardian Museum in 1869 by 

 L. Ewbank, Esq., M.A., Clare College, Cambridge, still remains, 

 so far as I have seen, the only example of a Dinosaurian genus 

 from the Oxford Clay which has a general affinity with Iguanodon. 

 As in all the Dinosaurs collected from the great Pelolithic period 

 extending from the Oxford to the Kimmeridge Clays, the articular 

 extremities of the bone show in their pitted surfaces evidence of 

 having had terminal cartilages, though these do not appear to have 

 been so thick as to have modified materially the forms of the articu- 

 lar ends. Thus the bone is devoid of epiphyses. And since epi- 

 physial growths among the lower vertebrates have a definite relation 

 ro the activity of the animal type in which they are found, as is 

 shown by their occurrence in Anura and Lacertilia, it would seem 

 likely, since Dinosaurs are to a large extent Reptilian in their osteo- 

 logy, that this condition of the articular surfaces bespeaks animals of 

 sluggish habits, and therefore, it may be, of cold blood, notwith- 

 standing that a not dissimilar condition marks the articular ends 

 of bones in the larger Cetacea. 



This femur is 1 foot and | inch long, with a slight anteropos- 

 terior flexure forward in the lower third of the shaft (PI. VI. fig. 1). 

 The bone is stouter and has its articular ends more expanded, and 

 pertained to a stouter type of limb than the femur of Hadrosaurus 

 or any of the figured American Cretaceous Dinosaurs ; its articular 

 ends, also, are wider in proportion to its length than in Scelidosaurus, 

 Megalosaurus, or Iguanodon. 



At the proximal end the shaft is triangular in section, being flat 

 on the outside and compressed towards the inside ; and the proxi- 

 mal articular expansion extends inward, so as to have an extreme 

 width of 4^ inches. The articular surface may be regarded as con- 

 sisting of two portions. An inner subspherical part corresponds to 

 the head or ball of the femur (figs. 2 & 3, b) ; it is irregularly sub- 

 circular, moderately convex, and looks upward, obliquely forward, 

 and inward : the extreme front-to-back width of this part of the arti- 

 culation is 2| inches, though its posterior outline is not regularly 

 convex. The continuous outer portion of the articulation is sub- 

 quadrate or slightly oblong when seen from above, obliquely con- 

 cave from within outward, and slightly convex from front to back, 

 where it measures 1£ inch wide, and has the posterior border 

 rounded more than the anterior border. Looked at from the outside 

 the articulation is directed inward and slightly forward, but ex- 

 tends to the limits of the bone. From this long articular surface 



m2 



