22 
The phalangial formula differs from all hadrosaurian reptiles in which 
the manus is known by having only two phalanges in digits IV and V, with 
the terminal ones flattened hoof-like bones, instead of the usual rounded 
bony nodules. These differences are clearly indicated in the following 
table: 
Digital Formulas of the Hadrosauridce 
Thespesius 
edmontoni, 
No, 8399, 
Geol. Surv., 
Can. 
Thespesius 
annectens 
(Marsh), 
No. 5060, 
A.M.N.H. 
Kritosaurus 
incurvimanus 
Parks, 
Univ. of Toron- 
to Museum 
Parasaurolophus 
walkeri 
Parks, 
Univ. of Toron- 
to Museum 
Number of phalanges in digit 
II 
3 H 
3 H 
3 H 
3 H 
Number of phalanges in digit 
III 
3 H 
3 H 
3 H 
3 H 
Number of phalanges in digit 
IV 
2 H 
3 
3 H? 
3 
Number of phalanges in digit 
V 
2 H 
3 
4 
3 
H signifies terminated by a hoof-like ungual. 
Brown 1 has called attention to the incorrectness of the manus in 
Thespesius annectens as originally assembled by Marsh, so that the evidence 
for the phalangial formula of that species rests entirely upon specimen 
No. 5060, A.M.N.H., described by Brown, and fortunately in such preser- 
vation as to furnish indisputable evidence. 
In the left manus of the Edmonton specimen the phalanx V 2 ? ( See 
Figure 6), is very likely the distal articular end of V 1 , which is much shorter 
than the right element and which appears to lack the distal end. 
“A carpal bone is preserved in each hand, in the same position, viz., 
at the ulnar side of the end of the radius. In addition, a smaller carpal 
bone was found in the right hand, at the middle of the end of the ulna, 
but a corresponding second carpal was not found in the left hand”. The 
carpals in Kritosaurus incurvimanus Parks 2 have similar ossifications, but 
in Thespesius annectens, as shown by Brown 3 there are two, rounded, ossicle- 
like ossifications one above the other at the junction of the radius and 
ulna. 
Although the elongation of the metacarpals, the rather loose articula- 
tion of the phalanges, and the imperfectly ossified carpus would indicate 
a manus little used as a means of locomotion, the functional hoofs on all 
the digits seem to show that they may have been of much use as sustaining 
organs when assuming a quadrupedal pose in feeding from or near the 
ground. 
Pelvic Arch and Hind Limb 
The pelvic arch and hind limbs conform closely to those of Thespesius 
annectens (Marsh). All the bones of the arch are present and perfectly 
preserved, except the distal halves of both ischia, which were eroded away 
before the specimen was discovered. The shafts of these bones appear 
1 Bull. Am. Mus. Nat, Hist., vol, 31, 1912, p. 106. 
s University of Toronto Studies, No. 11, 1920, p. 37. 
* Op. cit., p. 106, Fig. 1. 
