1909-10.] Morphology of the Manus in Platanista gangetica. 513 
centrale. At the ulnar margin, again, the absence of ulnar e and pisiform, 
as well as the fusion of carpale 4 + 5, showed a marked difference from the 
customary arrangement in Hyperoodon. 
In all my specimens the metacarpals were distinct bones. M i of the 
pollex articulated with carpale 1 and possessed two phalanges : M ii with 
carpale 2 had five phalanges : M iii with carpale 3 had four phalanges : M iv 
with carpalia 4 + 5 had four phalanges : M v, the minimus, with carpalia 5 + 4 
as well as with ulna had also four phalanges. In the youngest specimen 
the terminal phalanx was not ossified. 
The following schemata show the modifications in my specimens. 
Scheme 1, corresponding with fig. 2, represented the condition which 
approached most closely to Hyperoodon, for in it carpale 1 was a distinct 
bone from the radiale. Scheme 2, figs. 1 and 3, was the most usual arrange- 
ment ; radiale and carpale 1 were fused together. Scheme 3, illustrated by 
fig. 5, showed the fusion of the os centrale with the radiale-carpale. 
Scheme 4, illustrated by fig. 4, showed fusion of ulna with conjoined 
carpalia 4 and 5, and of carpale 1 with radiale. 
Scheme 1. Scheme 2. 
Min. Ann. 
Ph 4 Ph 4 
I I 
M v M iv 
\ 
C 5 + C 4 
Ulna 
Med. 
Ind. 
Pollex. 
Ph 4 
1 
Ph 5 
Ph 2 
1 
M iii 
| 
M ii 
Mi 
I 
C 3 
C2 
1 
C 1 
\ / Gen. I 
intermedium radiale 
Radius 
Min. 
Ann. 
Med. 
Ind. 
Pollex. 
Ph 4 
Ph 4 
i 
Ph 4 
i 
Ph 5 
Ph 2 
I 
| 
M v 
1 
M iv 
1 
M iii 
M ii 
1 
Mi 
C 5 + C 4 
C 3 C 2 Cl 
\ / Cen. + 
intermedium radiale 
Ulna 
Radius 
Scheme 3. 
Scheme 4. 
M v 
M iv 
Miii 
M ii M i 
/ 
1 
1 1 
C 5 + C 4 
C 3 
C 2 Cl 
j 
Bi Cen. + + 
intermedium radiale 
Ulna' 
Radius 
M v 
M iv 
M iii 
M ii 
Mi 
\ 
1 
1 
| 
C 5 + C 4 
C 3 
C 2 
C 1 
+ \ // Cen. + 
Ulna intermedium radiale 
Radius 
It is customary to place the genus Inia and possibly Pontoporia in the 
family Platanistidse, though I cannot speak from personal observation of 
the constitution of the carpus in these genera. Sir Wm. Flower, in his 
memoir on the skeleton of a young Inia geojfrensis* figured and named 
the bones in the carpus in accordance with the nomenclature in man. He 
spoke of scapho-trapezium, lunar, cuneiform, unciform and magno-trapezoid ; 
* Trans. Zool. Soc. Lond ., p. 105, pi. 25, Nov. 22, 1866. 
