2 
study of the material on which Lamb's species marginatus was based and 
the skulls above mentioned, arrived at a conclusion similar to that reached 
by Parks and accepted his new nomenclature. Gilmore definitely chose 
ttte better skull, Oat. No. 2869, Geol. Surv,, Canada, as the type of Latnbe- 
osaurus lambei Parks (5, page 34). 
Although Parks proposed the new nomenclature, he states li The 
resemblance of both species of Corythosaurus ( C . casuarius and <7, inter - 
medius) to the heads referred to Stephanosaurus by Lambe and herein pro- 
visionally named Lambeosaurus lambei , is sufficiently great to suggest a 
congeneric position for all three species ” (14, page 57). In the same paper 
Parks refers Parasaurolophus to the Saurolophinae instead of the Lambeo- 
saurinae (14, page 6). 
Nopcsa went still further and suggested that the hooded and spiked 
hadrosaurs were the males of the flat-headed forms (11). 
It is evident from these observations that students of the Hadrosau- 
ridae are not in full agreement. Since the National Museum of Canada 
has perhaps the best known collection of skulls of hooded hadrosaurs, the 
writer undertook a study of the subfamily dealing particularly with the 
skull characters to determine what are generic or specific characters and 
what should be ascribed to individual variation. Limb proportions were 
also compared. 
Material Studied. The first move in this research was to prepare all 
the skulls of hooded hadrosaurs in the collections of the Geological Survey, 
which were still in their field wrapping. Thus eighteen skulls have been 
assembled for study. Some of these are incomplete and poorly preserved, 
but others are nearly complete and show splendid details. Among these a 
splendidly preserved specimen (Cat. No. 8676) of a moderately young 
individual adds greatly to our knowledge of Corythosaurus. The skull was 
disarticulated, but complete except for the lachrymals, quadrates, quad- 
ratojugals, articulars, and right jugal and surangular. The greater portion 
of the skeleton is preserved back to the sacrum but it has been only partly 
prepared. This specimen shows for the first time in the corythosaurs the 
complete narial passages, complete prevomers, and the impression of the 
homy beak. It is referred to Corythosaurus excavatus Gilmore (4) . 
A well-preserved skull and jaws with part of the skeleton (Cat. No. 
8704) of Corythosaurus intermedius Parks give some additional informa- 
tion pertaining to the skull and fore limbs of this species. This specimen 
is considerably smaller than either of Parks' specimens, but it seems similar 
in all important details. 
A nearly complete skeleton, representing an undescribed species of 
Lambeosaurus (Cat. No. 8703), gives details regarding the skeleton and 
skin impression in this genus. This is the first case known to the writer 
where skeletal parts have been found associated with a skull of Lambeo* 
saurus , except for parts of the hind limbs and the ischia with specimen No. 
351, Geol. Surv., Canada. Gilmore referred another specimen, in which the 
skeleton was preserved, No. 8503, Geol. Surv., Canada, to Lambeosaurus 
(5, page 35) , but that specimen is here referred to Corythosaurus cf. infer- 
medius. 
