48 
DR. W. KOWALEYSKY ON THE 
Dimensions. 
Hyopotamus. 
Hempstead. 
Hempstead. 
Height, anterior ........................ 
19, 22 
271 
Breadth, anterior ...................... 
14, 17 
20 
Depth, antero-posterior 
22, 22 
281 
The unique specimen of the lunar I possess from Puy, although agreeing entirely 
with that from Hempstead, is somewhat too much crushed to admit of accurate mea- 
surements. 
The pyramidal (Plate XXXVIII. fig. 5, p) has the shape which is so characteristic of 
it in all Paridigitata. We may remark, in reference to this bone, that it is the least 
changeable of all the carpal bones, its shape being very similar, even in animals of 
widely different families and even orders. For instance, it is very like in both 
Paridigitata and Imparidigitata ; and a pyramidal of Ehinoceros is hardly to be dis- 
tinguished from that of a Hippopotamus. We may suppose that, as this bone has a 
very similar function to perform in all Ungulata, it did not change its shape, while the 
other bones, more directly acted upon by the different condition of life, did. 
The pyramidal of Hyopotamus presents therefore a certain likeness to that of an 
Anoplotherium , and also to that of a common hog ; the chief distinction lies in the fact 
that all its edges are much sharper, and not so much blunted as in Suidse ; this applies 
particularly to the ridge separating the facet of the ulna from the facet for the pisiforme 
(Plate XXXVIII. fig. 5,jp). 
The distal surface, adapted to the outer proximal facet of the unciform, is shaped very 
much as in all other Paridigitata. 
I have this bone only from Puy. 
Dimensions. 
Height 18^ 
Greatest antero-posterior depth . . .18 
Breadth 12 
The pisiform is wanting; it is, however, not a very important bone, partaking more 
of the character of a sesamoid than of a true carpal. 
The second row of the carpus. — I could not find the trapezium in any collection, although 
a facet on the radial side of the trapezoid and the second metacarpal clearly show that 
it was present. As the first digit is always abortive in all living and fossil Ungulata, 
the trapezium, which is the true carpal bone of this digit, has lost all its importance. 
However, it is to be seen in Hippopotamus and Anoplotherium (Blainv. Ost. Anopl. 
pi. iii.), where it articulates with the posterior face of the trapezoid, and assists in 
holding the second metacarpal in Hippopotamus , or the rudiment of the second in 
Anoplotherium. It is present in the Suidse (Plate XXXVII. fig. 4, tz) ; and I found it 
