38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8o 



sions we have discussed a series of five minute rounded marks, whose relative 

 position is precisely the same as the termini of the pedal toes in the' track 

 described. These marks seem therefore to indicate the impression of the right 

 pes. If so they give a trackway width of 33 mm. and an estimated stride of 

 the same foot of 42 mm., thus indicating a rather wide-bodied, short-legged 

 form. This form is provisionally included in the genus Exocampe Hitchcock, 

 the species being designated as delicatula in allusion to its delicate proportions. 



A series of footprints, one of several trackways impressed on the 

 undulating surface of a large slab of Hermit shale (No. 11,519, 

 U. S. N. M.), seems to be referable to this species. The specimen 

 was found one-quarter of a mile west of the sign " Red Top " on the 

 Hermit Trail, at the head of Hermit Gorge by Mr. G. E. Sturdevant, 

 of the Park Service, who discovered it lying loose on a slope about 

 30 feet above the Hermit-Supai contact where it had been exposed 

 to weathering, which to some extent accounts for the distinctness of 

 the minute tracks impressed upon the upper surface. 



m 



<? 



m 15 



Fig. 16. — Batrackichnus delicatula (Lull). Type. No. 2,146, 

 Yale Museum; right nianus (a) and pes (ii) natural size. (After 

 Lull.) 



The trackway, 300 mm. in extent, crosses the lower right hand 

 portion of the slab shown in plate 12. The hindfoot has a length of 

 10.5 mm, and width of 13 mm. There are five digits, and a tracing 

 of the foot plan, when placed upon Lull's figure of the pes, though 

 slightly larger, agrees precisely in the placement and arrangement of 

 the toes. The digits are slender, radiating, progressively lengthening 

 toward the outside. The fifth, much reduced in length and widely 

 set ofif from the others, has its origin far back on the sole and is 

 directed strongly outward. As in the type, the sole is indistinct, 

 though a few imprints seem to indicate that it was broadly rounded 

 behind. The hindfoot, as shown by Lull, is placed directly behind 

 the forefoot. 



The forefoot has a length of 7 mm., a greatest width from tip to 

 tip of first and fourth digits of 10 mm. There are four widely 

 radiating digits apparently without claws, although Lull thought he 

 detected " distinct impressions of terminal claws." Manus turned 

 strongly inward toward the axis of the direction of luovement. First 



