Vol. 68.] 



IN THE ' PERMIAN EOCKS OF HAMSTEAD. 



659 



From rocks of acknowledged Permian age, however, either in 

 Britain or upon the Continent of Europe, all the Hamstead forms — 

 or, at all events, closely-allied forms or varieties — have been cited. 



Tjpe Hi. ICHNIU3I SPH^KODACTYLUM Pabst. Of this type there 

 are nineteen specimens in relief (casts) and one specimen as 

 an impression. (See figs. 11 & 12, p. 661.) 



The footprints included in type Hi are characterized by the 

 impression of a broad and massive ball, and show a distinct heel. 

 The width of the footprint exceeds the length. There are five 

 toes, with blunt ends, which often leave rounded impressions. The 

 toes vary considerably in their spacing, sometimes being widely 

 spread open, at other times close together. Most commonly the 

 2nd, 3rd, and 4th toes are close, with the 1st and 5th toes well 

 separated from them and occasionally bent a little back towards 

 the heel. Sometimes the 1st and 5th toes have left no impression. 

 The toes turn, to some extent, towards the middle of the track, 

 especially so in prints of the forefoot. The prints of the fore 

 feet are always smaller than those of the hind feet, and show 

 toes proportionately shorter. Sometimes distinct markings indicate 

 the places of the joints of the toes ; and, more rarely, fainter 

 markings afford distinct evidence of a wrinkling of the skin of 

 the foot. The first toe of both feet is the shortest, and the 4th 

 the longest. Track-measurement I is always distinctly smaller 

 than track-measurement II. 



Measurements. 



H [main tj'pe]. 



ICHNIUM 

 SPHiEEODACTTLUM 



(Rothliegende). 



Minimum. 



Maximum. 



Average. 



Average. 



Fore foot: 



Length 



cms. 

 6-0 

 7-5 

 not 

 present 

 1-0 

 1-5 

 1-8 

 1-0 



cms. 



10-0 



11-9 



1-5 



2-8 

 3-4 

 4-0 

 2-5 



cms. 



7-7 

 9-5 

 1-0 



2-0 

 2-7 

 31 

 21 



cms. 

 9-0 

 10-2 

 2-1 (often absent) 



2-8 

 3-4 

 4-3 



2-6 



Breadth 



1st toe 



2nd toe 



3rd toe 



4th toe 



5th toe 





Hind foot: 



8-5 

 90 

 0-5 

 1-2 

 2-0 

 2-5 

 not 

 present 



12-5 

 13-0 

 1-6 

 3-2 

 4-6 

 5-0 

 4-0 



9-7 

 11-0 

 1-2 

 2-1 

 3-0 

 3-8 

 2-5 



10-2 

 11-0 

 2-6 

 3-4 

 4-2 

 5-3 

 34 



Breadth 



1st toe 



2nd toe 



3rd toe 



4th toe 



5th toe 





Track-measurement I ... 

 Track-measurement II ... 

 Width of track . . . 



8 

 16 

 12 



14 

 25 

 17 



11 

 19 

 14 



13 



22 

 18 





3a2 



