48 
MONOTREMATA. 
its spur is small, being less than a quarter of an inch in 
length. In the same collection is a smaller specimen than 
the above, in which the spines and the spur are more 
developed. 
The British Museum collection contains both sexes, and 
several specimens of each of the supposed species of 
Echidna; and there is, moreover, a half-grown specimen of 
the E. hys/rix. The E. sctosa is subject to some slight 
variation in tint, ns well as in the texture of the fur: the spines 
also vary slightly, being somewhat longer in some specimens 
than in others; yet the differences observable in individuals 
are not such as to render it difficult to distinguish the E. sctosa 
from the E. hystrix; nor can the differences existing between 
these two animals be those of age or sex, ns some have sup¬ 
posed. The E. hystrix is confined to the continent of 
Australia, whilst the present animal is peculiar to Van 
Diemens Land. M. Desmarest states, that the claws in the 
E. seiosa are narrower than in E. hystrix , but I have not 
found any constant difference in this respect; indeed, I have 
not been able to discover any other differences, excepting 
those observable in the fur and spines; and this leads me to 
doubt there being two species, and to suspect that die com¬ 
paratively humid climate of Van Diemen’s Land may have 
had the effect of causing the fur to become longer and more 
dense; and if so, the increased development of the fur would, 
in all probability, affect the grovrth of the spines, by robbing 
them of their nutriment. The present species, or variety, was 
first described and figured by Sir Everard Home, in the 
Philosophical Transactions for 1802, p. 357, PI. 13. 
Since the above was in type, the author has had an oppor¬ 
tunity of examining some specimens of the Short-spined 
Echidna preserved in spirits, and which are contained in the 
collection of the British Museum; one of these, a full-grown 
female, furnished the following dimensions: — 
