MR. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE, 359 
Dimensions of the Bones of the Arm. 
| Tasmanian /Tasmanian.|Tasmanian.| yy Caith- eer)|| 
| | skeleton. | No. 1. No. 2. es aa | ees | 
| 
Humerus. | inches, | inches. | inches. | inches, | inches. inating | 
Teenie phi sorts saseg ceciaie sala sions aw 2s | 192 | 22 | 182 203 20 174 
Breadth (vertical, or from the radial to the 83 9 8 81 
ulnar border) of head... 0.0.25 cen vee } 4 ; a eae eed 
Breadth at narrowest part............0....- 6 14 6 63 (E> 6 
Breadth’ at‘lower end ....5..0.....0.0-0% .-| 10z 113 93 114 103 9 
Phickn exstat ben dies . itels\ci cm sles’: cGea Jet peck 8i 83 Tex oe 8 Ae 
Mhickniess at Middle vy. ce vist setcigieres cise sinis «aise 4y AD ear: 4 
Radius. | 
Length (between middle of each extremity ; S or 
WItHOULEPIPN YSIS) s\:- 6. ete scececaeee } 132 = 2 12 SBE ets 
‘Breadth at mpperjend.) o/s seek das vase pal Obes 72 6 72 Set 53 
read Ghat dle npr nity feisty er oiaisyayernatevays ai 6 u 54 63 62 53 
BrCARGM AL AON ERTONG 2 wrateuse certie oes a Son es 6 72 93 83 83 7 
Ulna. 9 
IVI Bos dds oo Cov aseso eae aeRO omnes 123 14 11} 123 12 103 
Breadth at upper end, including olecranon ....| 10 12 104 12 11 10 
Breadihvajmiddlopaesc. ave sh asys ate issn ae 54 5 57 43 5 5 
Breadth ap, lOWer end ern ejee cig oide.6 s05,0; 66 «= 93 9 83 8} 8 
Greatest width of interosseous space............ 2 23 2 Deal teeters 
The carpus (Pl. LXI. fig. 1) is very remarkable on account of its width and short- 
ness, the bones of which it is composed being so extended laterally as to appear almost 
as if ina single row. As in most of the Toothed Whales*, ossification of the carpal 
elements advances more rapidly than in the Whalebone-Whales ; and in the older speci- 
mens the contiguous surfaces of the bones are brought into close apposition. In the 
younger individuals each bone is surrounded, except on its smooth free (dorsal and 
palmar) surfaces, by a layer of cartilage; and consequently its exterior presents the 
peculiar and characteristic appearance described at p. 326. Moreover, in many cases, a 
kind of epiphysial ossification has taken place in this cartilage, so that the bones are 
surrounded by a more or less complete case of thin osseous matter, which appears 
ultimately to unite with them (see Pl. LXI. fig. 4). This mode of ossification of the 
carpal bones, by a peripheral as well as a central nucleus, is, I believe, peculiar to the 
Cachalot. It has occurred to a much greater extent in the carpus of the entire 
skeleton than in the detached limb figured at Pl. LXI. fig. 1; indeed, in the latter, the 
peripheral ossifications were so small and so slightly adapted to the contiguous surfaces, 
that, their attachments having been lost during maceration, they could not be replaced 
with certainty, and so do not appear in the figure. 
All the specimens agree in the number and relative position of the carpal elements. 
Besides a bone projecting freely from the ulnar side of the carpus, probably correspond- 
* Orca is an exception. 
3D2 
