30 
“While the upper and lower jaws referred to T. marginaius may rank 
as paratypes, if they are associated, the species obviously rests primarily 
upon the 'remains of one individual’. The other specimens referred to are 
not cotypes, and the author is not at liberty to select any of them as a 
lectotype to the exclusion of his primary type. If the latter be indeter- 
minate, valid generic characters may be drawn from the paratypes, and if they 
also be indeterminate, then from other specimens subsequently referred.” 
In 1916 Brown 1 calls attention to the fore limb of Corythosaurus as 
having the radius much longer than the humerus, and infers that Lamb 
was correct in his first reference of the front leg to the genus Trachodon in 
which the humerus is longer than the radius. In the table below I have 
compiled from several authorities the comparative lengths of the fore 
limb bones of various members of the Hadrosauridse, and I find that all 
the crested forms in which the fore limb bones are known, except Parasau- 
rolophus, have the radius longer than the humerus, whereas it is always 
shorter in the non-crested types. It would appear more than probable 
from this evidence that the fore limbs pertaining to the skulls referred to 
Stephanosaurus, when known, will have the limb proportions of the other 
crested hadrosaurs. Brown may have erred in considering Lambe’s original 
reference of the limb to the genus Trachodon correct, but he certainly was 
right in believing it did not pertain to a helmet-crested form. 
Comparative Measurements of Hadrosaurian Fore Limbs 
Name 
Length 
of 
humerus 
Length 
of 
radius 
Length 
of 
ulna 
Mm. 
Mm. 
Mm. 
Stephanosaurus marginatus Lambe, type 
683 
632 
708 
Kritosaurus incurvimanus Parks, type 
630 
555 
610 
1 Trachodon mirabilis (Cope) 
501 
440 
500 
Parasaurolophus walkeri Parks, type 
520 
496 
560 
Hypacrosaurus altispinus Brown, para type 
580 
700 
750 
Saurolophus osborni Brown 
610 
620 
680 
Corythosaurus casuarius Brown, type 
"Radius much longer than humerus”, 
Brown 
The elimination of the fore limb and associated bones of the “single 
individual” (No. 419, Geol. Surv., Can.) from further consideration as 
pertaining to a helmet-crested hadrosaur, leaves the evidence for the genus 
Stephanosaurus as used by Lambe resting upon the maxilla and dentary 
which were subsequently selected by him as being characteristic of that 
genus and species. An examination of these specimens shows that they did 
not pertain to the same individual. Both were labelled as coming from the 
west side of Red Deer river, 1| miles below the mouth of Berry creek, 
but the maxilla was collected August 1, 1898, whereas the dentary was 
not discovered until August 19 of the same year. The difference in the 
date of collection, coupled with the fact of their having been assigned 
separate catalogue numbers by Mr. Lambe, implies their distinctness as to 
individuals. 
iBulI. Am. Mus, Nat. Hist., vol. 35, Nov. 2, 1916, p. 710. 
