8 Watson, The Upper Liassic Rcptilia. 



massiveness cf the fifth digit, and seems to be supported 

 by a curious specimen at Manchester. 



This specimen is a sph't slab of hard calcareous shale 

 of light yellow colour, which contains the distal phalanges 

 of a Plesiosaur limb, and the impression of the proximal 

 portion, surrounding this limb in certain areas is a tliin 

 dark brown film, whose distribution is shewn by the black 

 areas of y^?^. 3 ; this film has a curious and distinctive 

 appearance, and is, I think, certainly the preserved skin : on 

 the anterior border it keeps quite near to the bone, but 

 posteriorly it forms a large expansion which, I think, is 

 probably natural, and represents the posterior extension, 

 whose presence was so probable in Microcleidiis. 



A brown film, similar to that which surrounds this 

 Plesiosaur paddle, also occurs in connection with some 

 Icthyosaur skeletons at Manchester. 



The hind limb o{ Microckidus Jionialospojidylns is solely 

 represented by the femur, which is present in the Man- 

 chester specimen L. 7077. 



The femur is a slender bone with concave anterior 

 and posterior edges, its shaft is small and of oval section, 

 the distal end shews two articular facets. 



The bone is }^6 cms. long and 19 cms. wide distally, the 

 head is nearly hemispherical, being 8 cms. in diameter, 

 and is confluent with the great trochanter, which is of 

 very large size, its proximal termination forming a face 

 5 cms. square, inclined at 45° to the long axis of the bone. 

 This face and the head of the bone are pitted, and in life 

 must have been covered by the same cartilaginous coat. 



The great trochanter gradually subsides into the 

 shaft of the bone, which on its lower surface exhibits a 

 triangular raised and roughened area, which marks an im- 

 pprtant muscle attachment. 



