384 THE PORTLAND OOLITE PERIOD. CHAP. 



Femur. This bone, of crocodilian type, but more sigmoidal, more 

 compressed, and with less definite condyles, is ii'4 inches long, 

 2*1 wide near the proximal, and 1-9 wide near the distal end, and 

 1*35 where narrowest (two-fifths of the length from the distal end). 

 It is thickest near the upper end, rzo inch, and thinnest from the 

 middle toward the distal end, 0-95. The bone is compressed so as 

 to be almost carinated on the upper or forward edge ; striated lon- 

 gitudinally and roughly near the proximal end by the attachment 

 of tendons; more finely striated near the distal extremity. The 

 curve of the head of the bone is like that of crocodile, and there 

 is a trochanterial tubercle on the exterior surface, 3-35 inches below 

 the head, matched by another less distinct on the opposite surface. 



A tubercular projection on the inner face enlarges the curved 

 area of the head of the bone, and gives to the end a rhomboidal 

 shape. The lower end is very indistinctly marked for condyles, 

 and finishes with a curve, which probably corresponds to the aquatic 

 life of the race. Both extremities appear to have lost portions 

 which perhaps were cartilaginous. 



Tibia. A pair of short strong triquetral bones, the end outline 

 of the head trapezoidal, that of the distal end ovato-acuminate, has 

 been found at Garsington, with bones of steneosaurus. Length, 

 4-15 inches; breadth, i'8 at the head, and 1-15 at the lower end; 

 these ends having their surfaces converging at an angle of 30, 

 and their long axes diverging about 30. The upper adherence 

 of fibula is distinctly marked. It resembles the tibia of chelonia, 

 and agrees in shortness with Cuvier's notice of the bone at Hon- 

 fleur. See Diagram CLXXXVL, figs. 3, 4, 5, 6, 7. 



STENEOSAURUS GRACILIS. n.s. 



The Portland rock has yielded this interesting species of crocodile. 

 Mr. J. W. Mason, a diligent explorer of the geology round Oxford, 

 during his residence in the University noticed a fragment of the 

 animal thrown on the road ; afterwards by his labour, and that 

 of my assistant Henry Cowdell, a large spheroidal block of sand- 

 stone which had concreted round the bones was carefully broken, 

 and the head, with cervical vertebrae, was recovered. Other parts 

 of the animal may have been included in other such blocks, but 

 none were discovered among those masses which could be examined. 



