WEALDEN CROCODILES. 429 



angles to the exposed plane, and fractured across the middle, one extremity being 

 buried in one of the halves of the slab, and the other in the opposite half. B/ per- 

 mission of the Trustees of the British Museum, I was able, in 1841, to remove the 

 matrix from the two extremities of the same vertebra, and so demonstrated that 

 both articular ends were equally but slightly concave. 



The length of the body of the vertebra examined was . 

 Vertical diameter of the articular extremity . . . 

 Transverse diameter of the articular extremity 

 Ditto of middle of the body ...... 



Ditto of entire vertebra, including the transverse processes . 



Height of entire vertebra, including spinous process . 



From the lower part of the centrum to the base of the transverse 



process .......... 2 6 



The suture which joins the neural arcli to the centrum is conspicuous ; it forms 

 an ascending angle or curve at its middle part. The body of the vertebra expands 

 in a greater degree to form the subconcave articular surfaces than in other biconcave 

 vertebrae of the same length ; and both in this character and in its smooth surface 

 and circular transverse contour at the lower part, the Goniojjholis resembles the 

 Streptospondylus more than it does the Teleosaurus. 



The transverse processes of the lumbar and anterior caudal vertebrae are long, 

 straight, and comparatively slender ; those of the sacral vertebrae (PI. 7, *. «) are 

 relatively thicker, and the spaces enclosed by their expanded extremities are smaller 

 than in either the Teleosaurs or Crocodiles. The antero-posterior extent of the two 

 sacral vertebrae is three inches two lines. 



The ilium (ib., i) is broader than in the existing Crocodilians ; the bifurcation of 

 the proximal end of the ischium (ib-, is) is more marked, and the iliac branch is more 

 regularly rounded ; the pubic branch is longer, more slender, and its articular end is 

 more regularly convex ; the distal or low^er part of the ischium expands into a 

 relatively broader plate. This character is still more conspicuous in the pubis 

 (ib., p), which equals the ichium in breadth, and begins to expand much nearer the 

 proximal extremity tiian in the existing Crocodiles. In these modificatious of tiie 

 pelvis, as well as in the biconcave structure of the vertebra, the Crocodilian of the 

 Purbeck limestone approaches nearer to the characters of the Enaliosaurs ; and we 

 may infer that its habits were more decidedly marine than are those of existing 

 Crocodilians. The caudal vertebrae were provided with long, narrow, unanchylosed 

 chevron bones. 



The portion of the lower jaw preserved belongs to that part of the left ramus 

 included between the articular extremity, which is broken off, and the commence- 

 ment of the dental series ; it measures 1 foot 6 inches in length, and 5 inches in 

 greatest depth. In these proportions, and the curve of the lower margin, it deviates 



