FOSSIL FOOTPRINTS OF THE JURA-TRIAS. 



493 



including the metatarsal pad, .343 m. Length of foot, .440 ni. Distance between the 

 tips of the lateral toes. .'iSo m. Length of step, 1.02(1 ni. Width of trackway, .305 m. 



Although this is one of the lai-gest of the Connecticut valley tracks, that of Allo- 

 saurus would far exceed it in size for the estimated length of the footpi'iut of the latter 

 would be at least .720 m., as against .445 m. for the Gigandipus. 



Type specimens, nos. | and ,^,-, of the Hitchcock cabinet, on reddish shale from the 

 Lily pond. Turner's Falls, Massachusetts 

 (fig. 11). .y:\ui. 



The second species of Gigandipus, the 

 G. minor of Hitchcock, has been removed 

 to Apatichnus for which it seems to possess 

 greater affinities. 



Genus Hyphepus E. Hitchcock. (Web foot.) 



Hyphepus E. Hitchcock, '58, pp. 07, 

 189. 



Generic characters. Bipedal, tetra- 

 dactylous track. Hallux incumbent, curv- 

 ing sharply back\vard. There seems to be 

 a web between the anterior toes and they 

 are apparently clawless, except the third. 

 No phalangeal pads are visible on any of 

 the specimens. Caudal trace present, gen- 

 erally passing through the footprints. 



This form occurs at the same horizon 

 with Gigandipus, which it resembles except 

 for its smaller size, the presence of the web 



and the apparently clawless condition of left pes. X \. From the type specimen, no. i",, in the Hitoh- 



the lateral digits. It is placed provisionally cock cabinet. The bone restoration is based upon the foot 



r^• T ,1 1 ii 1 i- 1 • of AUosaurus, slishtlv modified from the mounted specimen, 



near Gigandipus thougii the relationship 



no. 290, of the fossil reptile collection of the American museum 



may not be a very close one. , of natural history. 



Fig. 11. Gigandipus caudatus E. Hitchcock. Imprint of 



Hyphepus fieldi E. Hitchcock. 



Hyphepus fieldiY,. Hitchcock, '58, pp. 97, 189, pi. 17, fig. 2; pi. 35, fig. 11; pi. 41, 

 fig. 2; pi. 42, fig. 2. 



