Tlie Geology of Coimaulai. 199 



and the hinder lobe of ^V are broken away ; the remaining 

 portions of the last two teeth have lost their enamel, and their 

 whole substance indeed appears to have been converted into 

 pseudomorphs of the originals and their surface characters 

 obscured by calcareous matter, but their general form remains 

 sufficiently evident to show by their straight sharp ridges that 

 they could only have belonged to a Halraaturus. The dental 

 series in this jaw measures by estimate 40mni., the sockets 52*5, 

 and the anterior depth of the mandible is 29mm. In size, 

 therefore, as in general facies, it agrees fairly with H. dryas, 

 and to that species it is provisionally referred. The identification 

 is supported by the presence of a second but left mandible from an 

 aged individual ; in this all the teeth of the molar sei'ies are 

 in place, but like the last so fragile, that an attempt to remove 

 encrusting matrix had to be abandoned. Enough of the 

 imperfect premolar, however, is visible to show the size and form 

 of the tooth. From these and from the length of the true molars 

 little doubt remains as to its identification with the same species 

 as the pi'eceding jaw. 



Femora. No entire skeletons of extinct Macropods have as yet 

 been found or at least described. In the large collection of their 

 remains accessible to me there are indeed but one or two instances 

 of bones and teeth found together under circumstances suggestive 

 of their specific co-identity. All the species but one being 

 founded on jaws, the attributions of bones to certain species 

 which have been hitherto or are still made by authoi's, are 

 therefore conjectural and at the best approximative. But since 

 measurement enables us to refer every recognisable bone 

 provisionally to one or two or three species, we may fairly allow 

 our choice so limited to be guided by the extraneous conditions of 

 the case. It should at the same time be remembered that 

 identification by measurement proceeds on the assumption that 

 the proportions of the animal in question were the same as those 

 found in the living species taken as a base of comparison, an 

 assumption which under the circumstances cannot be verified. 

 Under the impression, however, that it is better to get as near as 

 possible to accuracy, in spite of uncertainty, than to neglect 

 enquiry because of uncertainty, I venture to attribute to this 

 species the bones which seem to pertain to it. Among those are 



