1858.] HUXLEY — STAGONOLEPIS. 457 



would divide the plantar impression into a shallow outer portion 

 and a more deeply concave inner portion. A line drawn from the 

 emargination to the interspace between the first and second digits, 

 again, would divide the concave inner surface into a deeper external 

 portion and an internal portion, the latter gradually shallowing 

 towards the inner side, and passing into the impression of the inner 

 digit, which diverges so much from the direction of the others, and 

 seems to have beeny^comparatively so thick and short, that it might 

 well be termed a thumb. The proximal portion of this thumb seems 

 at first to terminate in a strong curved impression convex outwards 

 and forwards, and deepest internally, which has somewhat the shape 

 of a comma set transversely ( •- ). 



The distance from the emargination to the end of this impression 

 is 1|- inch ; beyond it is an interval of f ths of an inch ; and then 

 follows a shallow longitudinal mark, ^ inch long and nearly i inch 

 broad, which takes a direction nearly parallel with that of the ungual 

 phalanges of the other digits, and terminates opposite the base of 

 the ungual phalanx of the second digit. 



The last-mentioned features are only to be made out by exami- 

 ning the tracks very carefully by artificial, or by very oblique 

 natural, light*. Whether, as I originally supposed, the deep comma- 

 shaped impression is the mark of a nail covering the second phalanx, 

 or whether it has been produced by the first phalanx, — the longitu- 

 dinal mark being the true impression of the second phalanx, — is a 

 point I will not take upon myself to decide. A concave surface, 

 rising anteriorly, connects the impression of the proximal moiety of 

 the first digit vn.th that of the proximal phalanges of the second 

 digit. This impression, which is about an inch long, is very deep, 

 especially at its posterior end, and consists of two divisions, joining 

 at an angle, which is open outwards. The posterior division is 

 shorter and broader than the anterior, and the two would answer 

 very weU. to two phalanges : the anterior division is succeeded by a 

 third elongated and much fainter impression, about 1|- inch long, 

 broad and tolerably deep at the base, but gradually tapering and 

 fading away anteriorly. This appears to be the impression of the 

 ungual phalanx of the digit ; so that it would appear that there were 

 three phalanges in this dig-it, that the direction of the proximal one 

 is straight forwards, that of the middle phalanx forwards and out- 

 wards, and that of the distal or ungual phalanx still more outwards ; 

 so that the three describe a kind of curve, convex inwards. 



The impression of the third digit is like that of the second, except 

 that the distance between what appears to be the end of the proxi- 

 mal phalanx and the base of the ungual phalanx (corresponding with 

 the * anterior division,' spoken of above) amounts to fuUy J inch, 

 while in the second toe it is not more than -1- inch. Perhaps there 

 were two phalanges here. The impression of the ungual phalanx 

 is, as was stated above, 1-^ inch long. 



* I had not done this when my account of Stagonolepis was given to the 

 Society, and hence, in the abstract of my commimication, the comma-shaped im- 

 pression is described as the mark of a " thick, short, and much-curved nail." 



