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Show 1894.] MAMMALIAN HAND AND FOOT. 375 Hand,. Scaphoid. Radiale. Naviculare. Prox. row. Centrale. Lunatum. Triquetrum (pyramid.). (Pisiform.) Centrale. Intermedium. Ulnare. Foot. f Naviculare tib. \ (tuberos.). f Naviculare fib. 1 (lat.). Talus s. s. m . I Astragalus. Ingonum. ° (Calcaneum.) As regards the distal row there cannot be any doubt that the trapezoid and uncinatum are homologous with the middle cuneiform and the cuboid. As the internal cuneiform (Erethizon, M a n sometimes) and the external (Cryptoprocta) can be divided into two bones, we must look for the homologous bones in the hand ; and I think that the radial part of the trapezium (sometimes a free ossicle in M a n ) corresponds to the tibial or the plantar internal cuneiform, and that the head or proximal part of the magnum (Man), or the lateral part of the centrale (e. g. Centetes), corresponds to that bone which is situated proximally to the external cuneiform in Cryptoprocta. I cannot prove beyond all doubt that this is the second centrale, but there seems to be no other explanation. Consequently the distal row would be as follows :- Hand Trapezium. Trapezoid. Magnum. Carp. tars. dist. 1. Foot. Internal cuneiform j Plan tare. \ Dorsale. Middle cuneiform. f External cuneiform s. s. \ Triangulare, B. I Cuboid. Carp. tars. dist. 2. f Carp. tars. dist. 3. { Centrale 2. f Carp. tars. dist. 4. Unciform. 1 (separated: [ Carp. tars. dist. 5. J Ziphius). P.S. (April 23, 1894).-Since I read this paper I have found a specimen of Euphractus minutus in the Nat. Hist. Museum in which there is a very well-developed praehallux, like a metatarsal bone (see Plate X X I . fig. 7). There is also a muscle between the Ph. and the first metatarsal bone. EXPLANATION OF THE PLATES. PLATE XX. SKELETON of Mammalian Hands and Feet. Fig. 1. Right foot of Dasypus, 3/2 enlarged (p. 356). 3' 2. Right hand of Centetes ecaudatus, 3/2 enlarged (p. 356). 3. Right foot of Centetes ecaudatus, 3/2 enlarged. 4. Right foot of Bathyergus maritimus, 5/3 enlarged (p. 356). 5. Right foot of Erethizon dorsatus seen from above, nat. size (p. 357). 6! Praehallux of Erethizon, seen from behind, 3/1 enlarged. 7. Right hand of Mlurus jidyens, 5/4 enlarged (p. 358). 8. Right foot of Mlurus fulyens, nat. size. 9.' Astragalus of Mlurus seen from behind, showing the division into " talus " s. s. and " ti igonum." 25* |
