258 ZAGLOSSUS. 



(1905) states that in his series of nine Proechidnas are specimens even more 

 thickly haired than Dubois claimed for the type of mllosissima, but adds that 

 he and Dr. Hartert differed as to which should be considered young animals, 

 for there was no way of comparing the skulls. The dense character of the pelage 

 may be retained in the adult, as is the case apparently of the specimen from 

 British New Guinea, made the type of the race barioni by Thomas. The 

 thickness of the hairy coat can not of itself be considered a specific character 

 since even the small series of specimens at hand shows much variation in this 

 respect. Possibly the extreme condition shown by the villosissima specimens 

 is in part a concomitant of youth, as has been suggested by earlier writers. 

 The lack of definitive cranial characters, together with the absence of trenchant 

 differences in external features or geographical range, seems sufficient ground 

 for relegating villosissima to synonymy under hruijnii. 



To recognize four or five races of Proechidna all of which may occur to- 

 gether in the western peninsula of Papua seems a rather anomalous proceeding, 

 particularly since these are not separated by any structural peculiarities. The 

 case is somewhat paralleled by that of the Australian Echidna in which the range 

 of variation is so great as to have led at various times to the recognition of 

 several races, although now but one form is accorded to that continent. Wliile 

 I have not seen the type of either bartoni or goodfellowi, a careful study of 

 the descriptions of these two races does not reveal any diagnostic charac- 

 ters, and it seems best to consider these names for the present, at least, as 

 synonyms. 



As long ago as 1868, Krefft reported the discovery of Echidna-like remains 

 in the WelUngton bone and breccia caves of New South Wales, Australia, and 

 he figured a portion of a humerus. Later, Owen made further reports on addi- 

 tional fragments discovered in these caves. He figured a nearly complete 

 humerus that appears to belong to Zaglossus rather than to Tachyglossus as 

 I shall later show. This important discovery points to the former coexistence 

 of the two genera in Australia, and is of special interest in its zoogeographic 

 bearing, since at the present day both are found in New Guinea; Init the Echidna 

 alone survives in Australia. It follows therefore that the Proechidna was 

 already well differentiated from the Echidna long before Papua was sundered 

 from Australia, so that it is not a recent Papuan derivative from an Echidna 

 stock, developed here through isolation. But rather the two genera have long 

 existed side by side. 



The distinctive characters of the AustraUan fossil Proechidna are insuffi- 



