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Genus, Irenesauripus 1 new genus 
Genotype, Irenesauripus mclearni new species 
Generic Characters. Large; semidigitigrade ; functionally tridactyle; 
toes well separated; heel of variable width, but always completely impres- 
sed; weight borne equally by the three toes and the metatarsal pad; phal- 
angial pads not well defined ; claws acuminate ; no manus or caudal impres- 
sions. 
This genus is tentatively referred to Lull’s family Gigandipodidae, 
though it fails to meet all the requirements as given by Lull in that there 
is no impression of the hallux or the tail. The hallux had probably moved 
up on the foot sufficiently to leave no impression. The caudal trace is not 
always present in the Triassic forms. 
Tracks of this genus were probably made by some of the larger carni- 
vorous forms. 
Irenesauripus mclearni i 2 new species 
Plates I and II; and Figure 1 
Type . Cat. No. 8548, Geol. Surv., Canada, consists of a slab with the 
last three tracks of a trackway of sixteen impressions. 
Locality and Horizon. Peace River canyon, north side, about 2 miles 
upstream from Gething’s mine, on a stratum 290 feet above Grant seam, 
Gething member of Bullhead Mountain formation. 
Description. Tracks of this species are the most numerous of all 
those in Peace River canyon and were observed at various horizons from 
below the Grant seam to well above the horizon from which the type was 
collected. The tracks vary from 11 to 16 inches in length. Normally 
they are almost in a direct line and the stride is approximately three times 
the length of the track, but these characters vary with the nature of the 
surface and the speed of the animal. 
The longest stride in the trackway of sixteen tracks, of which the type 
specimen is a part, was 1,065 mm. and the average 940 mm. In that part 
of the trackway not collected the imprints were almost in a direct line; in 
that part collected (the type), the animal appears to have halted rather 
suddenly, with the result that the stride is much shorter, the tracks are 
wider apart, and more weight was thrown on the heel. In this, as well as 
in another trackway of this species (Plate I), there is a depression at the 
back of the imprint that appears to have been made by the dragging of the 
central toe as the foot was coming to rest. In other trackways of this 
species this “drag” is not shown. 
The weight was borne equally by the three toes and the metatarals 
pad or the so-called heel. The heel is moderately narrow. The toes are 
separated w T eil back and there is no indication of a web or extensive pad. 
They taper gradually from near the proximal ends and terminate in rather 
sharp claws. 
Greatest length of track, from posterior edge of centre of heel to tip 
of digit III, 380 mm.; from posterior edge of heel to tip of digit II, 292 mm; 
from same point to tip of digit IV, 280 mm. Greatest breadth of track 318 
mm. Divarication of digits II and III, 37 degrees; of III and IV, 33 degrees. 
•Saurian or lizard foot of Peace River country, 
*Thi8 species is named in honour of Mr. F. H. McT.earn, who discovered the tracks. 
