QUATEENAET FAUNA OF GIBEALTAE. 



107 



The bone is 6"-2 long, the proximal end r-6 X l"-75, the distal l"-6 X l"-4 the least 

 circumference of the shaft 3"-4, and the perimetral index •548. In the same bone fiom 

 Ilford, No. 20816, B.M., the corresponding numbers are 6"-0, l"-6xl"-5, l"-8xl"-8, 

 3"-4, and -566. 



Taking this specimen as the type of the fourth metatarsal ia E. hemitoechus, it would, 

 so far as the above dimensions go, appear to be more robust in the shaft, and to have a 

 thicker distal extremity than the Gibraltar specimen. Subjoined is a Table showing 

 the relative dimensions of the bone in other species : — 



Dimensious of the fourth metatarsal in 

 EhlnQceros. 



Gibraltar specimen 



R. hemiUxehus, Grays, No. 20816 

 B. bitomis (iJ. heitlod) 



tH 



6-2 

 6-0 

 5-6 



1-6 X 1-75 

 1-6 X 1-5 

 1-6 X 1-6 



1-6 X 1-4 

 1-8 X 1-8 

 1-3 X 1-3 



3-4 

 3-4 

 3-1 





•548 

 •566 

 •553 



From the foregoing account of the Ehinocerine remaius it may be concluded : — 



1. That they belong to at least three individuals, varying somewhat in size and, ' 

 more particularly, in age. 



2. That notwithstanding these differences, there is no reason for supposing that 

 they represent more than one species, which was of about the same stature as, though 

 somewhat slenderer in the extremities than the existing R. bicornis. 



3. That in the dental and most of the osteological characters the Gibraltar Rhino- 

 ceros, if not identical with, more closely resembled the smaller of the two Thames- 

 valley species {R. hemitoechus i, Falc, R. leptorhinus, Owen, R. viercMi, Lartet) than 

 any other known extinct or recent form. 



' With respect to the proper appellation of the smaller Thames-valley Rhinoceros, which was regarded by 

 Dr. Falconer as identical with the species first distinguished by him in the Gower Caves and elsewhere under the 

 name of R. hemiicechits, and also with that previously described by Prof. Owen from Clacton, notwithstanding 

 aU that has been written, some difference of opinion may well be entertained. Although in this account of the 

 Gibraltar Rhinoceros I have employed the familiar term proposed by Dr. Falconer, I am by no means sure that 

 it would not be better to retain the name given to the Clacton species by Prof Owen. It is quite true that 

 R. leptorhinus, Owen, is not R. leptorhinus of Cuvier, which, though it appears to have included R. megarhinus. 

 Christol, and R. etruscus, Falc, does not seem to have embraced R. hemitoechus; but, for the reason that 

 Cuvier's t«rm is of uncertain application, has been pretty generally superseded by R. megarhinus, and that the 



