xiv MARINE REPTILES OF THE OXFORD CLAY. 



Fraas, in his account of the fore limb of Geosaurus suevicus, adopts this interpretation : 

 in that species the preaxial bone of the distal row is large and quadrate, the postaxial 

 very much smaller and roughly triangular (see ' Palseontographica,' vol. xlix. (1902) 

 pi. viii. fig. 3). If Fraas and Ammon are right, as they probably are, then the distal 

 row of carpais has entirely disappeared and the metacarpals articulate directly with the 

 radiale and ulnare. It is not, however, possible to be quite certain that the four bones 

 figured may not represent the two rows of carpais, the radius and ulna being lost. 

 Even in the specimen upon which Fraas' figure is founded, the displacement of the 

 bones is considerable and does not appear entirely to exclude this interpretation. Of 

 the metacarpals the first is large and plate-like, with a convex anterior and slightly 

 concave posterior border. The second, third, and fourth metacarpals are much more 

 slender, probably flattened, rods of bone, somewhat constricted in the middle ; the 

 second is the longest and most slender. Ammcn figures a fragment of the fifth 

 metacarpal, but this 1 cannot see. The first phalanges of the first, second, and third 

 digits are preserved ; they are small and seem to have been much flattened. The 

 whole limb must have formed a paddle-like organ, the digits being separated at their 

 tips only, if at all. Though so much altered from the form of the fore limb of 

 ordinary Crocodiles, the paddle is not very greatly reduced in proportion to the size of 

 the body, its apparent smallness being partly the result of contrast with the enlarged 

 hind limb ; probably it was not used for propulsion, but rather in maintaining the 

 balance of the body. 



The pelvis is for the most part destroyed, but portions of the ilium and ischium, 

 together with an impression of the rather slightly expanded distal end of the pubis, 

 can be made out ; unfortunately, the upper end of this bone is not sufficiently well 

 preserved to show its relations to the ilium and ischium. The hind limbs are very 

 well preserved, that on the right side being almost completely shown, though the tibia 

 and astragalus are represented by impressions only. The tarsus in the left foot is 

 complete and is very closely similar to that of Metriorliynchus Iceve, shown on 

 PI. X. fig. 3 of the present volume. In fact, the whole limb is very similar in the 

 two species, the only notable difference being, that while in Metriorliynchus Iceve the 

 tibia is more than a third of the length of the femur, in the present specimen it is 

 less. The numbers of the phalanges preserved in the digits are 2, 2, 4, 4, but the 

 terminal one is probably wanting in the second ; the phalanges are much flattened. 



