ME. ST. GEOEGE MIVAET OX THE SKELETON OF THE PEIMATES. 
353 . 
The plantar surface always offers a ridge, bounding posteriorly a groove for the 
tendon of the peroneus longus. 
As has been before said, according to Van Campen * there is in the Potto (Perodic- 
ticus) an extra bone situated in the transverse ligament enclosing the flexor tendons, 
and near the ento-cuneiforme. He has figured it below the detached tarsal bones, and 
it is marked +. 
It is noteworthy that in the species possessing the peculiar ossicle, already described, 
in the manus, this homotypal exceptional structure should also be developed in the pes ! 
Metatarsus. 
This segment attains its greatest absolute length in the second metatarsal bone of 
Simia. 
The metatarsus, as estimated, by a comparison of the length of the second metatarsal 
with that of the whole pes, is greatest in Hylobates f, where the first is about one-third 
of the second. In most it is above a quarter, but in the Nycticebinas and Cheiromys it 
is between this and a fifth, while in Galago and Tarsius the proportion is still less. 
The proportion borne by the metatarsus to the pes is exceeded by that borne by the 
tarsus to the same, in none so much as in Man, except Tarsius and Galago, where the 
latter proportion is still greater. In the Gorilla, however, the excess comes very 
near to that existing in Man. 
The metatarsus exceeds the tarsus in length in Simia, Hylobates, the Semnopithecinse, 
Ateles, Pithecia, Chrysothrix, Hapale, and Indris. In the others the tarsus equals or 
exceeds the metatarsus, and largely exceeds it in Man and the Gorilla, and still more 
in Tarsius and Galago, where it is much more than twice the length of the 
metatarsus. 
The proportion borne by the metatarsus to the spine is greatest in Tarsius, but it is 
very large also in Hapale and Cheiromys. 
The four Outer Metatarsals . — These metatarsals are always more or less enlarged at 
each end. Almost always the proximal ends are wider transversely than are the heads 
(i. e. the distal ends) of these metatarsals. The disproportion in this respect is greatest 
in Man, though the lower Simiidee approximate to him. In Simia, however, the heads 
are scarcely narrower than the proximal ends, and sometimes in the Nycticebinse those 
of the third and fourth metatarsals are absolutely broader. 
The proximal surfaces of these metatarsals, except that of the fifth metatarsal, 
are sometimes nearly at right angles to the long axes of their shafts, as is the case in 
the Simiinse J, especially in Simia. 
* Yerhandelingen der Koninklijke Akademie van Wetenschappen. Zevende Deel,1859, p. 21, &pl. 1. fig.Sf. 
f From Dr. Lucae’s measurements it appears that this proportion is sometimes greater in Simia than in 
Hylobates. Also that in Cynocephalus and Macacus the metatarsus is sometimes more than one-third of the 
length of the pes, and as 38-5 to 100 (see loc. cit. p. 317). ...= 
£ See Dr. Lttcae’s figures, pi. 3. figs. 1, 2, 5, 10. 
