362 ME. "W. H. FLOWEE ON THE OSTEOLOGY OF THE SPEEM-WHALE. 



bone which generally appears at the radial end of the distal row of the carpus. 

 Although in the manus of some forms, e. g. GloMocephalus, and some Lelphini, one 

 could scarcely hesitate, at first sight, to identify it with the trapezium, the following 

 considerations induce me to agree with Dr. Van Bambeke in naming it the first meta- 

 carpal. 



a. Its characters are in many species intermediate between those of a carpal and a 

 metacarpal bone. This is the case in Phocwna, Pseudorca, Physeter, and some Belphini ; 

 while in Monodon, and especially in JDelphinus tursio, it has perfectly acquired the cha- 

 racteristic elongation of a metacarpal. 



b. There is a great tendency for the metacarpal at the other extremity of the 

 series (the fifth) to assume many of the characters of a carpal bone, especially at its 

 proximal end. 



c. The most crucial test appears to be afibrded by its early ossification, corresponding 

 in this respect with the true metacarpals. Thus in the genus Orca, while there is but 

 a single ossific nodule in the middle of the cartilaginous carpus, the bone in question 

 is as well ossified as are the undoubted bones of the metacarpal segment. 



It is quite possible that the trapezium may be contained in the bone which I have 

 called above " scaphoid," and that this should, therefore, be named " trapezio-scaphoid ; " 

 but of this I am not able to furnish any proof. 



7. The cmieiform always directly supports the fifth metacarpal, and frequently some 

 part of the fourth. Moreover, in those hands in which the uhiar side of the carpus is 

 greatly reduced, e. g. GloMocephalus, the fifth metacarpal has even a connexion with 

 the ulna itself. This condition of the Cetacean carpus is illustrated in other mammals 

 in which the manus approaches or attains the form of a paddle, — as in the Seals, and 

 more distinctly in the Sirenia, the fifth metacarpal is in more or less direct relation . 

 with the cuneiform of the proximal row. The same occurs also in some terrestrial 

 mammals, as the Armadillos. 



Tlie carpus of the Cachalot follows the simplest type of the Cetacean manus, the 

 chief peculiarity being its shortness and lateral expansion, by which the bones of the 

 second row are, as it were, forced up between those of the first, so as to bring them all 

 nearly on the same level. There is, however, no difiiculty in identifying them. Accord- 

 ing to the foregoing propositions, they will represent : — the scaphoid or trapezio- 

 scaphoid (Plate LXI. fig. 1, s), the lunar {I), the cuneiform (c), the unciform (??,), the 

 trapezoid or trapezo-magnum {t), the pisiform [p). The symmetry of theii- arrangement 

 is well seen in the figure*. 



The digits are five in number. The bones of which they are composed are tipped 



at each end by a thin layer of cartilage, which in no instance among the specimens 



examined contained an osseous epiphysis ; nor is thei'e any sign of a terminal epiphysis 



having been united to any of these bones. This is somewhat remarkable, as in some 



* In Wall's description the distal epiphyses of the radius and ulna are taken for bones of the carpus. 



