I 



84 MR. A. L. ADAMS ON THE OSTEOLOGr OF 



side, and tibiae PI. XV. figs. 1 & 2, had every appearance of forming portions of the 

 same skeleton. The two naviculars in question (right and left) agree in dimensions; 

 but fig. 1 is the more perfect, and is in accord in eveiy respect with that of 2677a. 

 Royal College of Surgeons. The linear dimensions of the bone in question are well 

 shown in the figure. The calcaneal facet is 1-1 by 0-4 inch; whilst the arc of the cup, 

 by tape, is 3-3 inches. The same admeasurement on the convex surface, which is 

 considerably abraded so as to denude the facets, is 4 inches. The cuboidal facet has its 

 outline preserved, giving a surface of 2 inches by 1 ; the others are not defined, con- 

 sequent on abrasion. Thus, whilst the naviculars of the recent Indian (2677a, R. C. S.) 

 and the above closely consort as to dimensions, the same may be said of the astragals 

 referred to them ; indeed, to follow the comparison further, it may be repeated that the 

 tibiae of the two diifer inasmuch as the former is 14 and the latter 17 inches in length, 

 thus giving a shorter and stouter leg-bone to the fossil, just as obtains in the African in 

 comparison with the Indian, more especially, however, in the dimensions of the toe- 

 bones, as will appear in the sequel. 



3. The small right naviculare PI. XVII. fig. 7 has all the characters of a young bone ; 

 I therefore hesitatingly refer it to the smaller form. The facets extend to the margins, 

 as in the immature individual. The following are the dimensions of this specimen — 

 breadth 2-6 inches, depth 1-7 (about), arc of the astragaloid facet 2, arc of anterior 

 surface 2-8, thickness 0-8. The lower part of the bone being lost and a perpendicular 

 fracture prevent further reliable measurements. 



4. The smallest naviculare (fig. 8) had precisely the same characters as the last, 

 but is more imperfect; as far as relative comparisons go, it consorts well in dimen- 

 sions with astragalus PL XVI. fig. 3 ; whilst fig. 7 is equal to that of the Oxford 

 skeleton, being 2-5 inches in length, and therefore also very small, but much too large 

 for astragalus PL XVI. fig. 3. 



Summary. — Taking the navicularia generally, they indicate cogently one form of the 

 bone of the largest hind-foot bones I have yet described, and, doubtfully, intermediate 

 and pygmy forms. 



Cuboid. — There are three specimens of this bone in my collection, two of which 

 are fragments. They are divisible into large and small. 



1st. A Type.— The largest (represented in PL XVII. fig. 4) has lost its lower part, 

 including nearly the entire calcaneal and fifth metatarsal facets, by accident— enough, 

 however, remaining to establish its dimensions as compared with the bones just de- 

 scribed. It is too large for the naviculare (fig. 1), and also exceeds the dimensions 

 of the same bone of 2677 a, R. C. ,S. ; but it equals that of the Sumatran (B. M.) and 

 the largest fossil naviculare. The maximum thickness of the fragment at the middle of 

 the fourth metatarsal surface is 1 inch. It is the front aspect that is shown in the 

 figure, the margin a being the internal or cuneiforme attachment. The naviculare facet, 

 unlike that of the recent, is not isolated by a furrow, and is even only feebly indicated by 



