198 BRITISH FOSSIL REPTILES. 



The Cheirotlierian Ichnites resemble the foot-prints of a Salamander in having 

 the outer toe of the hind foot projecting at a right angle to the line of the mid- 

 toe; they recall the foot-prints of the toad in their unequal size. The fossil 

 remains, above described, from the Triassic deposits and localities exhibiting the 

 Cheirotherian impressions, justify the conclusion that they have been made by a 

 cold-blooded rather than a mammalian Marsupial animal, and by a species of the 

 class which includes Batrachians with a similar disproportion between the hind and 

 the fore limbs. On this hypothesis it is not less evident that the impressing vagrant 

 was quite peculiar and distinct from any known Batrachian or other reptile in the 

 form of its feet. The analogy of the Crocodilian reptiles would indicate the short 

 and freely-projecting digit to be the outer or fifth toe, whilst the closer corre- 

 spondence of the Batrachian feet would prove it to be the inner or first toe ; but 

 the thickness, relative size, and position of the remaining toes are peculiarities of 

 the Cheirotherian footsteps. 



Thus, in LabyrintJiodon we have a Batrachian reptile, and one that differs very 

 remarkably from all known Batrachia and every other reptile in the structure of 

 its teeth : it is also a Batrachian, which, with strong aflinities to the Sauria, 

 appears to have presented the same inequality of size between the fore and hind 

 extremities as does the so-called Cheirothere : and both the footsteps and the 

 fossils are peculiar to certain members of the Triassic formations. May we not 

 then be justified, upon this evidence, in adding the name Gheirotherium to Masto- 

 donsaurus and Phytosaunis among the synonyms of the genus Labtrinthodon ? 



I have already alluded to footsteps of a different but somewhat allied form, as 

 being probably those of the Lab. leptognatlvus. These footsteps actually occur 

 associated with those to which the name Cheirotherium has been given on the 

 same slab, in the sandstone quarries at Storeton, but are more Crocodilian in their 

 character. 



Since my first acquaintance with this type of reptile I have received and 

 described other specific and generic forms from Hindostan, America, and, as in 

 the instance of the species of Bi/tidostens, from a Triassic formation at the Cape of 

 Good Hope.^ 



Here the progress of time compels me to conclude the present work. To those 

 who encouraged me in the undertaking I plead the intervals elapsing between the 

 acquisitions of the subjects, and the frequent indication of a new form of Extinct 

 Reptile by a fragmentary fossil, calling for further research in the locality, and 

 lapses of time before additional evidences justified a reconstruction and a name for 

 the long lost monster. 



' ' Quarterly Journal of the Greological Society,' Marcli, 188-1. 



