Fishes 203 



the middle line in front of the first dorsal are more conspicuous than in 

 older specimens. They are about thirty-six in number, and relatively a 

 good deal smaller than in S. aculeata of 365 millimetres. In S. angelus 

 of 375 millimetres these spines are relatively smaller than in the younger 

 stage, hardly conspicuous, and very much smaller than in our S. aculeata, 

 which is of practically the same length. Head spines can be detected 

 in S. angelus of 240 and 365 millimetres, but grade insensibly into the 

 surrounding asperities. The nasal flaps are probably variable in both 

 species, and form no safe guide for distinction. Normally they seem to 

 be tucked away out of sight. & angelus, at 365 millimetres, is somewhat 

 more massive in appearance than S. aculeata, and differs a little in 

 some of its proportions. The width across the pectorals is contained 

 less than twice, across the ventrals about three and a half times in the 

 total length ; the length of the head is less by about one-third than 

 its greatest width, and occupies about one-third of the distance between 

 snout and anus. The eye is smaller than in S. aculeata, 1 its length 

 being equal to distances separating it from the spiracle and from the 

 anterior margin of the head directly in front of it, and is only about 

 one-fourth of the inter orbital width. The latter is equal to the distance 

 from the snout to a line joining the spiracles, but is a little less than 

 the distance between the spiracles. The hind margins of the pectorals 

 are broadly rounded in S. angelus, not more or less pointed, as in 

 S. aculeata. 



We are not acquainted with larger specimens of *S. aculeata. 



1 We are not in a position to affirm or deny the specific distinction of 

 Bonaparte's S. oculata from S. angelus. The former species is said by him to have 

 the eye larger than in his »S'. angelus, from which it does not otherwise appear to 

 differ in any important respect of which the author took. note. It appears to have 

 lacked both the vertebral spinulation and pointed pectorals of S. aculeata. 



26—2 



