160 MR. R. COLLKTT ON ECHTnNA ACANTHION. [Feb. 3, 



425 millim. The other specimens were smaller, had a length to the 

 root of tail of 12 and 12'5 inches, or, with the same calculation, a 

 total length of 325 and 341 millim. 



It is evident from Mr. Ramsay's short descrijition and measure- 

 ments, that U. acanthion is very nearly related to E. lawesi. The 

 same armature of the back with powerful and closely-set spines, 

 and a very scanty covering with hairs between the spines is found in 

 both ; and in both the claws on the hind feet show the same 

 mutual proportions of length, by which they easily may be distin- 

 guished from the South-Australian and Tasmanian species. 



Although Ramsay's description of U. lawesi, on account of the 

 limited materials, could not be very exhaustive, there still seem to 

 exist differences, which entitle us to separate the Australian form 

 from its neighbour on the other side of the Strait. I endeavour 

 below to touch upon the points in which E. acanthion seems to 

 differ from E. lawesi, although such comparison can only advanta- 

 geously be made with the specimens of E. lawesi themselves, which 

 I have not had an opportunity of seeing. 



Besides the short original description of the latter species, I have 

 just received in a letter from my friend Dr.Vinciguerra a few remarks 

 on a specimen in the Museo Civico, in Genoa, received in exchange 

 from Berlin, and examined by Dr. Gestro. 



The chief differ-ence between them seems to exist in the length of 

 the snout (and perhaps also that of the skull), which is perceptibly 

 shorter in E. acanthion than in the other species. 



As to the skull, there is unfortunately no exact statement given 

 of its length in Ramsay's short description of ^. lawesi. Only in the 

 type-specimen, the total length of which has been about 336 millim., 

 the length of the skull is said to have been four inches, or about 

 103 millim. This undoubtedly is on the whole larger than in equally 

 large specimens of E. acanthion. 



This seems also evident from another of the measures given. In 

 Ramsay's type specimen of E. lawesi, the total length of which is 

 about 336 millim., the distance from tip of snout to the ear is 

 (skin stretched) 4'5 inches, or 113 millim. In the Genoa specimen, 

 with a total length 377 miUira., the same distance is 120 millim. In 

 E. acanthion, on the other hand, the length of the skull is 93 millim. 

 in the young male with a total length of 365 millim. ; and even in 

 the largest specimen, tlie total length of which is 448 millim., the 

 skull does not exceed 1 1 1 millim. 



The length of the snout is measured in all Ramsay's four specimens 

 of ^. lawesi, and has been fourd to be as follows': — 



1 Calculated froui tbo Eugiish measuremeuts. 

 '■^ " From tip of snout to the eye 2'5 inches." 



