In length the metacarpus resembles that of the Ruminants, in which however it consists of but one bone; while in Pterodactyles there is a separate bone for each of the four fingers; they are closely united together without being blended. In some Pterodactyles the metacarpals of the short fingers are as fine as hairs, so that it is impossible that they should have articular facets on the carpus. In Ornithopterus the metacarpus has some resemblance with that of the bird, but the articulation with the phalanges of the finger for flight is stiff. In Pterodactylus and Rhamphorhynchus there is a free articulation. Burmeister remarks that the chief articulation of the wing in bats is with the carpus, while in Pterodactyle the articulation is with the end of the metacarpus. _The hand._ Von Meyer finds four fingers. It was formerly supposed that the order of the phalanges was 2, 3, 4, 4, but in the fly-finger this is not the case, Ornithopterus having but two. The number of joints in the other fingers is quite as irregular. In Pt. longicollum the thumb consists of but one joint. _The Ilium_ is more mammalian and avian than reptilian. _Pubis._ The pubis appears to have been excluded from the glenoid cavity, as in Crocodiles. It is more mammal-like than bird-like, and is to be compared with the marsupial bones. _The femur._ In certain Pterodactyles the proximal condyle of the femur resembles birds; but in other Pterodactyles the bone is more mammal-like in its straightness, and development of the upper condyle, and in the presence of a trochanter. _The tibia and fibula_ may be compared, from their great length, with birds and flying vertebrate animals. The fibula is style-shaped, like that of a bird, the lower part being wanting; while in bats the upper part is wanting. _The tarsus,_ of two rows, is best compared with that of reptiles. The number of constituent bones has not been definitely determined. _The metatarsus_ shows a certain return from the bird type to that of reptiles. _Foot._ Von Meyer never finds more than four toes, and sometimes a stump of a fifth. As a whole, the foot is Saurian-like. It differs from lizards in the number of toes, and approximates to Crocodiles. In Pterodactylus longirostris the formula of the toes is 2, 3, 4, 5, with a stump of two joints;--like lizards, if we abstract the outer toe; and like birds with four toes; but they are liable to variations. In Pterodactylus scolopaciceps and P. Kochi the formula is 2, 3, 3, 4 joints. In Winkler's specimen of P. Kochi there is also a stump of three joints. In Pterodactylus micronyx the formula is 2, 3, 3, 3, and a stump of two joints. In P. longicollum the number appears to be different from all the foregoing.