LIASSIC FORMATIONS. 
31 
opposite margin of the ulna is very convex ; the distal end is divided by a low angle 
between the surfaces for the outer and middle carpals of the proximal row. 
The carpal bones are six in number, three in each row. The proximal ones are 
the largest, but, of this row, the radial carpal, or ‘ scaphoid,’ is least ; it is of a trans- 
versely oblong figure, with its distal border divided by a low angle between the radial 
and the middle bones of the second row j this relation is better shown in the right 
than in the left pectoral fin. The middle proximal carpal, or ' lunare,’ is the largest, of 
a sub-hexagonal form ; the shortest side, toward the radius, is concave ; the side 
opposite the radial carpal is rather convex ; the other facets for the ulna, ulnar carpal 
(‘ cuneiforme’) and the two larger carpals of the second row, are nearly straight. 
The three carpals of the second or distal row increase in size from the radial to the 
ulnar side of the waist; the outermost being surrounded by three carpals and three 
metacarpals ; the metacarpal of the fifth digit extending along its ulnar side to articu- 
late with the ulnar carpal of the first row. In its relations to the metacarpals, the 
largest of the second row resembles the ‘magnum’ and ‘unciforme’ combined, of the 
mammalian carpus. The next in size answers to the ‘ trapezoides,^ supports the second 
metacarpal, and, at its opposite -border, fills the interspace between the radial and 
middle carpals of the first row. The radial carpal of the second row is the smallest 
of all ; it is wedged between that of the first row, the first metacarpal and the middle 
carpal of the second row : it answers to the ‘ trapezium.’’ 
The first metacarpal (ib., 56 ) is the shortest, 1 inch in length, it supports two 
phalanges, the last of which is 1 0 lines in length ; the whole length of this digit, 
including the metacarpal, is 2 inches. The second metacarpal is 1 inch 9 lines in 
length, and supports six phalanges, the last being 4 lines long; the total length of this 
digit, including the metacarpal, is 10 inches 6 lines. The middle metacarpal is 1 inch 
10 lines in length, it supports eight phalanges ; the total length of this digit, including 
the metacarpal, is 10 inches 6 lines. The fourth metacarpal is 2 inches in length, 
it supports seven phalanges ; the total length of the digit, including the metacarpal, is 
10 inches. The metacarpal of the fifth digit is 1^ inch in length, its proximal breadth 
is 1 inch; that of the first metacarpal being half an inch, and that of each of the three 
intermediate metacarpals ranging from 9 to 10 lines ; the outermost metacarpal sup- 
ports seven phalanges : the total length of the digit, including the metacarpal, is 
9^ inches ; the fifth metacarpal, besides being shorter and broader than the three 
middle ones, is more convex, and obliquely bevelled off at its proximal end, the radial 
side being shorter than the ulnar one. The phalanges of the fifth digit are more con- 
cave at their outer or ulnar border than the others. The first metacarpal is more 
concave at its radial border. All the phalanges are flattened and expanded at their 
extremities, the outer surface showing linear impressions, the middle part being 
smooth. The total breadth of the carpus is 4 inches 5 lines. The total length of the 
hand is 1 foot 1 inch. The total length of the pectoral limb seems to have been about 
