230 DR. R. W, SHUFELDT ON [Apr. 1, 



represented by an inconspicuous intercalated bit of tbin cartilage, 

 barely preventing tbe contact of the tibio-fibulare witb tbe first two 

 metatarsals. Proximal epiphyses of these latter, however, are 

 moulded to meet the ends of perfect articulation. Subcuboidal in 

 form, tarsale 3 is a well-ossified bonelet articulating with second and 

 third metatarsals, with tarsale 2, and with tbe tibio-fibulare, or tbe 

 co-ossified mass representing the elements of tbe ])roxinial row. Tbe 

 basal ends of the 2nd and 3rd metatarsals are markedly smaller than 

 they are in tbe 1st and 4tb, indeed in t!ie latter it has its proximal 

 extremity very conspicuously expanded. Tarsale 4 is a larger 

 nodule of bone that articulates with tbe tarsal elements upon 

 either side of it, witb the 4th metatarsal, and with tbe tibio-fibulare. 

 Finally, more remarkable tlian any of the rest is tarsale 5 ; it is a 

 wonderfully irregular bone in form, and peculiar in other respects. 

 It articulates by merely a vertical line witb the tibio-fibulare. 

 Externally it sends forward a prominent process that, by a trochlear 

 facet at its extremity, articulates with the basal phalanx of the 5th 

 metatarsal. It also articulates with tarsale and metatarsale 4, 

 while in the sole it sends downwards a strong process that serves for 

 muscular and other attachments. This latter is augmented by the 

 form assumed by tarsale 4 at its inner side, and it is this common 

 apophysis that gives attachment to some of tbe short plantar muscles 

 that, in my chapter on tbe myology (given above), may have been a 

 little diflPerently described, from tbe confusing propinquity of the 

 ossicles in question. So that a knowledge of this fact will make 

 clear in those premises what might otherwise be considered not an 

 exact description. Professor T. J. Parker, in bis studies otLacerta 

 viridis, considered tarsale 4 to be tbe "cuboid" (Zootomy, p. 152). 

 Vestiges of a very rudimentary character appear to be present in one 

 of my specimens of Ileloderma of a sixth pedal ray, it being in 

 connection witb tarsale 5 upon the fibular side of tbe ankle. 



The metatarsals differ in form but slightly from the metacarpals, 

 and these differences pertain more especially to tbe proximal extremi- 

 ties, and these have already been pointed out above. Still more in- 

 significant are the differences to be found between the corresponding 

 joints of the digits of manus and pes, and their numerical arrangement 

 is also similar. We saw in the hand that, passing from the radial to 

 tbe ulnar side, the fingers possessed 2, 3, 4, 5, 3 phalangeal joints, 

 respectively ; now in the foot, in passing from the tibial to the 

 fibular side these numbers exactly correspond, or we find 2, 3, 4, 5, 3 

 phalangeal joints to tbe toe respectively. 



An excellent diagnostic character twixt pes and manus in this 

 Lizard is to be found in the comparative size and furm of the fifth 

 metatarsal and the fifth metacarpal; in the case of tbe former it is 

 notably short and small, while in tbe latter quite tbe reverse of these 

 characters exists, for no especial curtailment of its length is to be 

 noticed, and in bulk it rather exceeds any one of the middle three 

 joints of the palm. 



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