FAUNA LOWER KEUPER SANDSTONE. 13 



another to the inner side of the maxilla, and a row on the 

 mandible fitting into a hollow between. These crushing 

 teeth are, however, supplemented by the horny covering 

 of the maxilla and mandible. The premaxillse are pro- 

 longed into a pointed and recurved beak, which was also 

 encased by a horny sheath. The skull is short, broad and 

 somewhat pyramidal in form. The species described and 

 figured was probably two to three feet in total length, and 

 the feet are considerably larger than many of the prints 

 usually attributed to it. There are, however, many of the 

 full size of Huxley's figure, and the smaller ones present 

 exactly the same features, the principal one being that 

 the fourth digit is the longest, and this cannot too strongly 

 be borne in mind when investigating the footprints. 

 Unfortunately the prints are usually imperfect, and at 

 times it is difficult to allot the correct numbers to the 

 digits shown. 



The hind feet, you will notice, are the most perfectly 

 preserved ; the fore foot, or maims, is not so good, but I 

 have here the photograph of a fore limb in the Shrews- 

 bury Museum (Plate L, Fig. 2). The hind limb of the 

 same not having been preserved, it is impossible to state 

 the proportion in size between the pes and the maiius. 



The footprints are so intricately mixed on all the 

 surfaces recording them that it is not possible to trace — 

 or rather, I should say I have not succeeded in tracing — 

 any continuous track, or positively determining the fore 

 and hind feet of the same animal. This is readily ex- 

 plained if the Rhyiichosaurus was like the Sphenodon in 

 its habits, for on the only occasion on which I have had an 

 opportunity of observing the latter, where they had room 

 to move freely, they were intensely active without any 

 apparent object, darting about in all directions, and it 

 would have been a difficult matter to trace the tracks of 



