572 BRITISH FOSSIL REPTILES. 



The distal surface (PI. 67, fig. 6) is oblong and almost flat save where it becomes convex 

 on being continued from the basal upon the radial surface ; it is feebly concave trans- 

 versely at its middle half, but this is not continued, deepening, so as to divide the palmar 

 part of the joint into a pair of trochlear condyles. The length of this metacarpal is 

 5 inches 9 lines ; the breadth of the proximal end is 4 inches ; of the distal end 3 inches 

 2 lines ; the breadth of the middle of the shaft is 2 inches 3 lines. 



The largest of the proximal phalanges extracted gives a length of 5 inches 5 lines ; 

 with a breadth of the proximal end of 4 inches, and a breadth of the distal end of 3 inches 

 7 lines. The breadth of the middle of the shaft is 3 inches ; and this seems not to have 

 been more than 1 inch 7 lines in ancono-thenal diameter, but the thenal surface is 

 partially crushed in. The anconal surface is smooth and flat save toward the expanded 

 articular ends. The proximal surface, moderately concave, appears to have been adapted 

 to a distal articular surface of the simple character of the metacarpal last described (PI. 67, 

 fig. 6). The distal surface of the phalanx is moderately trochlear, i.e., with a feeble 

 transverse concavity along its middle half ; it is strongly convex throughout in the opposite 

 (anconothenal) direction. The size of this proximal phalanx indicates it to have belonged 

 to one of the larger middle digits. 



Of the instructive terminal phalanges, the most entire forms the subject of figs. 4 

 and 5 of PI. 6S. The small proportion preserved of the thin, smooth, punctate, articular 

 surface shows a partial depression at i, fig. 4 ; but the bone is so slightly abraded where 

 that smooth crust is wanting as to aff'ord a fairly true figure of its general shape, which is 

 almost flat, with a feeble sinuosity. The anconal border («) is most produced ; conse- 

 (juently that surface of the phalanx is longest ; but it is little more than half as long as it 

 is broad. The thenal surface is made concave lengthwise by the thenal production of the 

 terminal lobes of the distal end (PI. 68, fig. 5). There is no appearance of these being 

 articular. I regard them as the free termination of a last or ungual phalanx, and to show 

 a modification of that end like the terminal phalanx of the second toe in Iguanodon 

 {' Dinosaicria,' PI. 48, a, 3). 



Not any of the fragments of phalanges suggested a structure for supporting a terminal 

 claw, such as exists in Ilegalosanrus. The fore-foot of Oinosaurus, as represented by the 

 bones above described, was a short, broad, massive member, relating chiefly to progressive 

 motion, and suggests the huge species, if not, like Iguanodon, phytophagous, to have been 

 a mixed feeder. 



Ilium.— The mass of matrix with the portion of the skeleton of Omosauriis figured 

 in PI. 72, reduced to one ninth of the natural size, includes, with the sacrum, both the 

 iliac bones and a large portion of the right ischium. The left ischium and both pubic 

 bones, one of which was almost entire (PI. 73, figs. 4 and 5), were wrought out of the block 

 in the course of exposing the rest of the pelvis upon which they were lying dislocated. 



The length of the ilium is 3 feet 5 inches ; that of the antacetabular portion is 1 foot 



